Frozen droppings of prehistoric ground squirrels are chock-full of DNA from ice-age beasts, including woolly mammoths, a mysterious big cat and a huge array of other organisms, revealing a remarkably detailed genetic snapshot of ancient life in Canada's rugged Yukon.

Although the genetic material of large creatures was found in the ground squirrels' poop, these rodents were not carnivores. They were opportunistic omnivores that feasted on a wide variety of plant material and fungi, as well as insects, rodents and carrion, just like Arctic ground squirrels (Urocitellus parryii) do today in the Yukon Territory and other parts of northwestern North America and Siberia.

But Arctic ground squirrels also have a habit of collecting and storing various objects in their burrows, which may have introduced additional DNA into the droppings over time, potentially explaining some of the genetic signals detected, the researchers cautioned. It's also possible that carnivores' DNA ended up in the burrows because they were attempting to prey on the squirrels, they added.

"The Arctic ground squirrels that are in the Yukon today act kind of like pack rats," study first author Tyler Murchie, a paleogenomics researcher with the Hakai Institute in British Columbia, Canada, said in a statement. "So they'll go into the landscape, and they'll collect a whole bunch of different bits of plant material and bones, seeds, and they'll bring it back to their burrow."

So whether these ancient rodents were feasting on carrion and other edibles or simply bringing it into their homes, these dropping help reveal the flora and fauna that lived in Beringia, an ancient region that once encompassed northeastern Asia and northwestern North America when the continents were connected by a land bridge during the last ice age. The findings were published Tuesday (June 9) in the journal Nature Communications.

Poop detectives

For the study, the researchers analyzed samples extracted from the poop pellets, which had been preserved for millennia in burrows within the deep permafrost of the Yukon, which borders Alaska. These droppings, the oldest of which date to around 700,000 years ago, have yielded an extraordinary treasure trove of ancient environmental DNA from numerous plant, microbial, fungi and animal species.

Notably, the genetic material from the 700,000-year-old ground-squirrel droppings ranks among the oldest DNA ever recovered and sequenced, according to the authors.

"The research shows us that ground squirrel coprolites, or droppings, preserve remarkably diverse genetic snapshots of ancient Beringia, making them exceptional repositories for understanding evolutionary and ecological change through the deep past," study co-author Hendrik Poinar, director of the Ancient DNA Centre at McMaster University in Ontario, said in the statement.

"It helps reconstruct paleoenvironments in much deeper time, providing insights into environmental change, megafaunal evolution, dispersal and ultimately extinction," Poinar added.

During their investigation, the researchers extracted ancient environmental DNA from a collection of ground-squirrel coprolites. This provided the team with sufficient quantities of well-preserved genetic material to reassemble more than 18 mitochondrial genomes, including those of woolly mammoths (Mammuthus primigenius), the now-extinct steppe bison (Bison priscus), horses (Equus), the snowshoe hare (Lepus americanus) and the Arctic ground squirrel itself.

A mitochondrial genome, or mitogenome, is the complete set of DNA found inside mitochondria — small structures located within cells that generate energy. The mitogenome assembled from the 700,000-year-old sample represents the oldest mitogenome ever recovered from ancient feces, the study reports.

The team also detected weaker genetic fingerprints from a range of other animals in the coprolites, including evidence of lemmings (Lemmus), caribou (Rangifer tarandus), gray wolves (Canis lupis) and a big cat — possibly a cougar or the extinct American cheetah (Miracinonyx trumani) — as well as fungi, bacteria and more than 200 groups of plants.

Given the rich archive of genetic material that has been uncovered, the findings could pave the way for future discoveries, according to the researchers.

"The thing I hope people take away from this kind of work is the unexpected mystery that you could find in remains that you might otherwise overlook," Murchie said in a video statement.

How much do you know about Earth's frosty past? Find out with our last ice age quiz!

Scientists analyzing 1,300-year-old human feces from the Cave of the Dead Children in Mexico have discovered that people often dealt with nasty intestinal infections more than a millennium ago.

"Working with these ancient samples was like opening a biological time capsule, with each one revealing insight into human health and daily life," study lead author Drew Capone, an assistant professor of environmental health at Indiana University, said in a statement.

Capone and colleagues used molecular analysis techniques to study 10 ancient desiccated feces samples — also called paleofeces — found in a cave in Mexico's Rio Zape Valley just north of the city of Durango in northwestern Mexico, that dated from A.D. 725 to 920. The researchers published their findings Wednesday (Oct. 22) in the journal PLOS One.

In the late 1950s, archaeologists excavated the Cave of the Dead Children and recovered human and non-human paleofeces, plant remains and animal and human bones from a large trash heap. The cave was used by people from the prehistoric Loma San Gabriel culture, who practiced small-scale agriculture, produced unique ceramics, lived in small villages and occasionally practiced child sacrifice. Archaeologists named the cave after the skeletons of children found there.

Previous studies of paleofeces from the cave revealed the presence of hookworm, whipworm and pinworm eggs, suggesting the people who deposited their feces in the cave were infected by a variety of parasites.

In the new study, the scientists used cutting-edge molecular techniques to detect additional microbes in paleofeces from 10 "distinct defecation events" with the aim of expanding their understanding of the burden of disease among the Loma people. "There is a lot of potential in the application of modern molecular methods to inform studies of the past," study co-author Joe Brown, a professor of environmental sciences at the University of North Carolina at Chapel Hill, said in the statement.

The researchers extracted DNA from the 10 paleofeces samples and then used polymerase chain reaction (PCR) to amplify the DNA of the microbes in the feces. Every sample had at least one pathogen or gut microbe in it, and the two most common were the intestinal parasite Blastocystis, which can cause gastrointestinal issues, and multiple strains of the bacterium E. coli, which were found in 70% of the samples. Also identified were pinworms as well as Shigella and Giardia, which cause intestinal illnesses.

The high number of microbes discovered in the paleofeces "suggests poor sanitation among the Loma San Gabriel culture from 600-800 CE resulted in exposures to fecal wastes in the environment," the researchers wrote in the study. People likely ingested the microbes via feces-contaminated drinking water, soil or food, the team added.

While these pathogen-associated genes persisted in the paleofeces for up to 1,300 years, there may have been even more pathogens in the samples that have since decayed and are no longer detectable, the researchers noted in the study.

Still, the new analysis revealed the DNA of pathogens that were not previously found in paleofeces, including Blastocystis and Shigella.

"The application of these methods to other ancient samples offers the potential to expand our understanding of how ancient peoples lived and the pathogens that may have impacted their health," the researchers wrote.

Two men in New York state have died of a rare fungal lung infection that they caught from bat poop — specifically, poop they were using or planned to use as fertilizer to grow cannabis.

Both men, based in Rochester, shared a love of "Mary Jane" and cultivated their own cannabis plants for personal use. They each developed a condition called histoplasmosis after breathing in spores of a harmful fungus known as Histoplasma capsulatum from bat poop, or guano.

The first man, who was 59-years-old, had purchased guano online to use as fertilizer for his cannabis plants. The other man, 64, was intending to fertilize his cannabis plants with guano he'd found in his attic following a "heavy" bat infestation.

The men developed an array of symptoms from their infections, including fever, chronic cough, extensive weight loss, blood poisoning and respiratory failure. Despite being hospitalized and treated with antifungal medication, both men died of their illnesses, according to a report of their cases, published Dec. 4 in the journal Open Forum Infectious Diseases.

Related: New cause of asthma lung damage revealed

The doctors who treated them said that their deaths should serve as a warning about the potential dangers of using bat guano as a fertilizer for any plants. This may be a particular issue for cannabis growers.

"Given the recent legalization and an expected increase in home cultivation of cannabis, along with the promotion of bat guano for this purpose, it is important to raise public awareness about the potential risk of using bat guano as fertilizer," the case report authors wrote. The authors added that they found numerous articles calling bat guano a "natural superfood" for cannabis plants due to its high concentration of nitrogen and phosphorus.

These recent deadly cases also "emphasize the need for protective measures, such as wearing masks when handling it," the authors added.

Histoplasmosis is a type of pneumonia caused by breathing in spores of H. capsulatum, a fungus found in soil and bird and bat droppings. In the lungs, H. capsulatum spores transform into mature yeast that can spread to other regions of the body via the bloodstream. However, the disease cannot spread between people or between people and their pets.

Each year, around 1 to 2 per 100,000 people in the U.S. are infected with histoplasmosis. Infections mainly occur in the Mississippi and Ohio River valleys, although cases have been reported in 14 states, according to the U.S. Centers for Disease Control and Prevention (CDC).

Only about 1% of people exposed to H. capsulatum develop symptoms. When symptoms do emerge, they usually occur within three to 17 days after exposure, and include fever, chills, muscle aches and chest pain.

People who have had a lung disease prior to being infected and those with weakened immune systems are more likely to develop severe forms of histoplasmosis, which can last for months or longer, and be deadly. Between 5% and 7% of patients hospitalized with histoplasmosis die as a result of their infection.

The men in Rochester had other existing diseases when they caught histoplasmosis, which may have worsened their infections. The first, for instance, had a condition known as emphysema, where the air sacs in the lungs are damaged, which restricts breathing. And both patients had histories of tobacco use, in addition to smoking marijuana.

The authors of the new case report say that commercial fertilizers containing bat guano should be tested for H. capsulatum before being put on the market. If that is not possible, products should be labeled with warning signs and provide instructions on how to use them safely, they said.

To minimize the risk of infection, the CDC additionally recommends that people avoid engaging in activities that may increase their chances of being exposed to H. capsulatum, such as cleaning chicken coops or exploring caves. Large amounts of bird and bat droppings, which may be found in an infested attic, should be removed by professional companies, the agency states.

This article is for informational purposes only and is not meant to offer medical advice.

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Endometriosis is notoriously difficult to diagnose. Now, scientists have devised a new way to spot the condition — by looking for a unique collection of metabolites in poop that could potentially be detected with a simple test.

These metabolites are made by microbes in the gut as by-products of their metabolism when the bacteria digest the food we eat. Some metabolites released by gut bacteria make their way through the digestive system and end up in our poop, which means they can be detected in a stool sample.

Scientists had previously identified a link between distinct changes in the gut microbiome — the community of microbes in the colon — and endometriosis, a debilitating disease in which tissue that normally lines the uterus grows elsewhere in the body. Endometriosis can cause chronic pelvic pain, inflammation and impaired fertility, and historically it's been difficult to diagnose.

Related: Endometriosis may quadruple risk of ovarian cancer, study finds

In the new study, published Friday (Oct. 11) in the journal Med, researchers demonstrated for the first time that a distinct signature of metabolites in poop could be used to efficiently flag the disease. The hope is that such a test could someday be incorporated into the diagnostic workup for endometriosis.

While the test wouldn't replace conventional diagnostic approaches, it could provide a simple way to check if a person likely has endometriosis before they commit to getting an invasive surgical procedure.

"When women suspect that they may have symptoms of endometriosis, they could take this non-invasive test and have some certainty that 'Ok, I might have this disease,'" Rama Kommagani, study co-author and an associate professor of pathology at Baylor College of Medicine, told Live Science.

In the U.S., it currently takes an average of 11 years for people with symptoms of endometriosis to be diagnosed. Some symptoms of the condition are non-specific, meaning they appear in many other diseases. For instance, chronic pelvic pain can also occur in conditions like fibroids or pelvic inflammatory disease.

The process of being diagnosed with endometriosis normally begins with doctors taking a full medical history of a patient and conducting a complete physical and pelvic exam. They may also choose to do an ultrasound or magnetic resonance imaging (MRI) scan. However, the only certain way to diagnose the condition is with a keyhole surgery known as laparoscopy.

A stool test could potentially ease this arduous process. To see if such a test is feasible, the study researchers compared the metabolites and bacteria found in stool samples from 18 women with endometriosis and 31 women without the condition.

They found that the people with endometriosis had lower levels of "beneficial" bacteria in their poop than people without the condition. These include Roseburia bacteria, for example, which have been shown to have anti-inflammatory properties.

The researchers also found that metabolites in the poop of women with endometriosis significantly differed from those in samples from those without the condition. In particular, one bacterial metabolite called 4-hydroxyindole was present in much lower levels in the stool samples of women with endometriosis than those without.

In separate experiments, the team transplanted cells from human endometriotic tissue into mice, effectively giving the rodents the disease. When the scientists injected the mice with 4-hydroxyindole, they found that the metabolite reduced the growth of the endometriotic tissue. Simultaneously, the levels of inflammation and disease-associated pain went down in the mice. This hints that 4-hydroxyindole may have some protective role against the disease — but this effect needs to be confirmed in studies with humans.

If the same patterns are seen in people, it is possible that low levels of 4-hydroxyindole could be used to diagnose endometriosis, while somehow supplementing the metabolite could potentially treat it, Kommagani said.

Kommagani and colleagues are now working with commercial partners to evaluate the safety and efficacy of 4-hydroxyindole as a potential drug to treat endometriosis. In addition, the researchers are now developing a stool test based on the findings of their study, and they intend to test it in a clinical trial.

The current study only looked at a small number of people with endometriosis, so an important next step is to determine whether the findings are generalizable to the wider population.

If everything pans out, the team hopes that such a test could be available to patients within the next two to three years, with the ultimate goal of releasing the test for at-home use, Kommagani said.

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The gut microbiome, the community of microorganisms that live in the colon, may shape a person's risk of developing chronic diseases, such as type 2 diabetes and heart disease. Now, scientists have developed a computational tool that they say can reveal how "healthy" a person's gut microbiome is, using data from a single stool sample.

Although the concept is intriguing, experts told Live Science they have reservations about how useful the new tool would actually be to patients.

The tool, called the Gut Microbiome Wellness Index 2 (GMWI2), gives users a score between -6 and +6. The higher the score, the "healthier" their gut microbiome reportedly is, and vice versa. In a recent study, published Aug. 28 in the journal Nature Communications, researchers found that the GMWI2 was 80% accurate at differentiating between a "healthy" gut microbiome, on the positive end of the spectrum, and an "unhealthy" one, on the opposite end. The tool was trained on stool samples from 8,000 people and then tested on samples from 1,140 people.

Anyone can freely download and use GMWI2, but they'll need a "basic computer science or bioinformatics background" to interpret the results, study co-author Jaeyun Sung, an assistant professor of surgery at the Mayo Clinic in Minnesota, told Live Science.

Related: The gut microbiome has a circadian rhythm. Here's how it might affect your health.

The team hopes that eventually, anyone will be able to get a gut health score from their local clinic by providing a stool sample, Sung said. However, other experts have expressed concerns about the potential utility of such a tool. They wonder what it means to have a "healthy" gut microbiome in this context and who might stand to benefit from learning their gut health score.

Defining "healthy"

GMWI2 is built upon a type of machine learning, an artificial intelligence (AI) tool that can make predictions about a piece of data based on a set of rules it has been trained to follow. Typically, scientists "train" the AI by providing troves of data from a given population, and then once it has picked up common patterns in that data, the tool can make predictions about new data from a different group of people.

In this case, the researchers trained GMWI2 to identify specific features of the gut microbiomes of people who have a disease — say, diabetes — and compare them to the gut microbiomes of people without that condition. They did this by feeding it data on the mix of microbes found in the stool samples from about 8,000 people from 26 countries on six continents.

Around 5,500 of those individuals had been previously diagnosed with one of 11 diseases, including colorectal cancer and the inflammatory bowel disease Crohn's disease. The remaining 2,500 people didn't have a diagnosis of any of the 11 conditions. After training the tool with these data, the researchers tested how well it worked on another 1,140 stool samples from patients who were either diagnosed with diseases, such as pancreatic cancer and Parkinson's disease, or not.

The researchers found that the higher a person's GMWI2 score is, the more closely their gut microbiome resembles that of someone who does not have one of these diseases. A lower score suggests the opposite — that their gut microbiome looks distinct from that of an individual with any of these conditions.

Unlike well-established diagnostic tools, such as colonoscopies for colorectal cancer, GMWI2 is not designed to diagnose specific diseases, the study authors emphasized. Rather, it's meant to flag subtle changes in a person's gut health that may hint that they're likely to develop a given disease, they wrote.

Instead of providing diagnoses, Sung said, the tool could potentially be used by people who are otherwise healthy but who want to optimize their gut health to prevent disease, he said. It may also be helpful to those who are more likely to develop a particular disease because it runs in their family, he suggested.

GMWI2 could also be used to assess how well someone's gut is recovering after they've been given chemotherapy or antibiotics, as both of these treatments can harm the microbiome, he added. These treatment-induced changes can weaken the immune system, making patients more vulnerable to future infections.

Related: Scientists unveil 'atlas' of the gut microbiome

No "one-size-fits-all" solution

Despite the potential appeal of a tool like GMWI2, experts told Live Science that they have some reservations about how it could be used in real life.

The study is a "heroic attempt" to tie specific gut microbiome signatures to either health or disease, said Willem De Vos, an emeritus professor of human microbiomics at the University of Helsinki who was not involved in the research. However, "one of the problems with the approach is that health is hard to define — health is more than the absence of disease," de Vos told Live Science in an email.

Some scientists argue that there is no universally accepted definition of health, because health is a relative condition. Health for one person doesn't necessarily mean the same thing as it does for another — for example, two people may get a GMWI2 score of +6, but the composition of their microbiome may completely differ. This can make it hard to define what a "healthy microbiome" is.

A person's health also changes throughout their lifetime, so any health scores that are garnered from a tool like GMWI2 would become "meaningless" unless they are repeated over time, said Dr. Fergus Shanahan, a professor and chair of the Department of Medicine at University College Cork in Ireland, who was not involved in the research but is an expert in the gut microbiome. The abundance of certain microbes in the gut also fluctuates daily, and can be influenced by a person's diet, stress levels or mood.

This means that a person who is trying to monitor the health of their gut microbiome after a round of antibiotics, for instance, would need to keep using the tool on a regular basis, such as every week or month, Sung said.

Furthermore, several versions of GMWI2 may need to be developed in order to tailor the tool to different populations, Shanahan told Live Science in an email. "Several studies have shown that the composition of the microbiome varies considerably in different ethnic groups, sometimes quite markedly," he said. This may be caused by varying social and environmental factors, including diet and lifestyle.

"Thus, any tool for measuring health of an individual must be adapted to the population within which the individual lives," Shanahan argued.

It's also currently unclear what people would do to alter a "suboptimal" GMWI2 score. In the paper, Sung and colleagues mention that it might prompt people to get more diagnostic tests or to modify certain aspects of their diet or lifestyle. However, without knowing what disease a patient has — if any — it may be difficult to implement any targeted interventions.

The team is now developing the next version of the tool, which will be known as the Gut Microbiome Wellness Index 3. (GMWI2 was an update to the more basic prototype, the Gut Microbiome Wellness Index, which was introduced in 2020 and trained on a much smaller number of stool samples.)

They aim to train the next iteration of the tool using at least 12,000 stool samples from a much more diverse cohort of people. They also plan to use more sophisticated machine learning algorithms to interpret the data, Sung said. Assuming they earn regulatory approval, it's possible that the tool could be put on the market within the next two years or so, he predicted.

This article is for informational purposes only and is not meant to offer medical advice.

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Editor's note: Since this story was published July 31, two Olympic triathletes have fallen ill following races in the Seine, although it's unclear if the illnesses were directly related to exposure to the river. Due to the sicknesses, Belgium’s triathlon mixed relay team withdrew from the Aug. 5 race and Switzerland's team changed its race lineup. 

Rain showered down on athletes, onlookers, can-can dancers and opera singers at the 2024 Paris Olympics opening ceremony on July 26, and more rain over the weekend reportedly drove an uptick in disease-causing bacteria in the Seine river.

This decline in water quality prompted officials to cancel the swimming portion of a training session for the triathlon events, and the men's race, scheduled for Tuesday (July 30), was postponed. Finally, on Wednesday (July 31), both the women's and men's triathlons were allowed to proceed, with athletes plunging headfirst into the Seine for a 0.9-mile (1.5 kilometers) swim before jumping onto bikes for the next leg of the race.

France and Great Britain snagged gold in the women's and men's races, respectively. But even as the athletes take the podium, there's more river swimming to come, as the mixed relay and marathon swimming events are scheduled for next week.

Are there any lingering concerns about the water quality in the Seine? And what risks could subpar water pose to the competitors? Live Science spoke with experts to find out.

Related: Will Olympic athletes ever stop breaking records?

Poop pollution

Paris invested the equivalent of $1.5 billion in making the Seine swimmable in time for the Olympics. The renovation involved connecting thousands of residences to municipal sewer systems and constructing a huge underground cistern. This massive tank, which holds 20 Olympic swimming pools' worth of water, is intended to prevent untreated sewage from flowing into the river.

Paris has a combined sewer network that captures stormwater and wastewater, funneling both to treatment plants. But in times of heavy rain, some untreated water is instead diverted into the Seine and its tributaries to prevent disastrous backups. The new basin beneath Paris helps curb such outflows by capturing excess water and then slowly releasing it back into the sewers so it can go through the normal treatment process.

This cistern was completed in May. But even so, when it rains in Paris, the quantity of bacteria-carrying poop in the Seine still spikes. In particular, rain comes with an uptick in Escherichia coli, a bacterium found in both human and animal feces.

"Elevated E. coli levels are to be expected following rain events," Sarah Lowry, a doctoral candidate in environmental engineering at Stanford University, told Live Science in an email. E. coli acts as a general indicator of fecal contamination, so its presence implies that other common poop-borne pathogens, such as norovirus and Salmonella, are likely also in the water. In addition to the germs from human wastewater, some of these pathogens come from animal feces that get washed into the river, Lowry noted.

After such an influx of poop, one can expect the related pathogens to then decline due to sun exposure and fluctuating temperatures in the water. In terms of how long that takes, "we are talking about days, not weeks in general," Patrick Gurian, a professor and the head of the Environmental Engineering Program at Drexel University, told Live Science in an email.

"In general, if levels of E. coli rise in a natural, moving body of water because of runoff from rain, those levels should start to drop when the rain stops," said Mia Mattioli, the team lead for the Environmental Microbiology and Engineering Laboratory within the Centers for Disease Control and Prevention's (CDC) Waterborne Disease Prevention Branch.

Related: What are the most polluted cities in the world?

"However, the time it takes for the levels to drop will depend on upstream runoff, surrounding land use, and drainage systems," Mattioli told Live Science in a written statement. Additional factors, such as the cloudiness of a given body of water, can also affect how quickly germs die off, Lowry added. "It's hard to say without knowing the specifics of a particular site," she said, but it typically takes one to two days.

Following the weekend's rain, another rainstorm hit Paris in the early morning hours Wednesday, The Washington Post reported. A few hours later, organizers met to discuss the results of the latest water-quality tests and deemed the water safe for racing. The rain let up around when the women's race started at 8 a.m.

"The results of the latest water analyses, received at 3:20 a.m., have been assessed as compliant by World Triathlon allowing for the triathlon competitions to take place," the organizers said in a statement sent to news outlets Wednesday. However, the Olympic organizers previously said the water samples used to make these decisions are taken 21.5 hours prior — which means they would have been taken before Wednesday's rainstorm. The test results from Wednesday have yet to be released.

What's the risk?

World Triathlon, the international governing body for triathlons, bases its water safety guidelines on the European Union's Bathing Waters Directive. These guidelines set a threshold for the E. coli level that's considered safe enough for swimming in inland waters: 900 colony-forming units per 100 milliliters (CFU/100mL).

That number came from epidemiological studies that looked at rates of illness among swimmers and then correlated them with the levels of an indicator bacterium, such as E. coli, in the body of water where they swam, Lowry explained. Such thresholds are specific to a given geography and type of water — salt versus fresh — so "there is no one number that is 'best' to set a threshold," she noted. That's why standards may vary among locations.

Paris Mayor Anne Hidalgo and Paris 2024 Chief Tony Estanguet took a dip in the Seine two weeks prior to the Games to demonstrate their confidence in its cleanliness. But notably, data later showed that E. coli levels were 985 CFU/100mL that day, The Associated Press reported. That's slightly above the "sufficient" threshold set forth in the guidelines.

So, what's the potential risk of swimming in poop-contaminated water?

In general, the various disease-causing germs found in feces can cause stomach cramps and diarrhea, which can lead to dehydration, Mattioli said. They can also cause ear, eye, respiratory and wound infections. "CDC cannot speak to the status of the Seine at present and defer to French authorities who are monitoring the water quality," she added.

E. coli, specifically, is not always a threat to human health — in this context, the microbe is being used as a benchmark to see if there's likely a concerning amount of poop in the water, Lowry emphasized. Most E. coli strains are harmless, but some can cause gastrointestinal problems and urinary tract infections. One type, called Shiga toxin-producing E. coli, can spark more-serious illnesses, involving bloody diarrhea and, in some cases, blood clots and kidney damage.

An individual's likelihood of getting sick after swimming in poop-contaminated waters varies depending on their existing immunity and their degree of exposure to the germs, Lowry said.

"The amount you ingest is usually the problem," Gurian said. Skin exposure can be an issue in some cases, but "by and large, the less you drink, the safer you are." In addition to avoiding swallowing the water, swimmers can protect themselves by wearing earplugs, nose plugs and goggles; covering any open wounds as much as possible with waterproof bandages and changing those bandages after swimming; and showering after swimming, Mattioli said.

Current weather forecasts suggest that more rain could befall Paris in the coming days, so the Seine's quality may continue to fluctuate. Only time will tell if the upcoming scheduled races will be postponed, downgraded to exclude swimming or moved to alternate arenas — or if anyone will wind up ill after braving the river's waters.

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Sperm whales blasted a "big dark bubble" of poop to prevent an impending orca attack off the southern coast of Western Australia.

Scientists witnessed the clever defense strategy unfold Tuesday (March 19) during a tourist excursion in Bremer Canyon, a whale-watching hotspot off the coast between Albany and Hopetoun. They described seeing a "cloud of diarrhea" permeate the water, and this rarely seen defense mechanism seemed to help the sperm whale pod escape what could have been a fatal attack by at least 30 killer whales, ABC News Australia reported. 

"It's called defense defecation," Jennah Tucker, a marine biologist with Oceans Blueprint, a marine and environmental sciences research organization, who was on the charter boat, told ABC. When the animals defecate, she said, they pass their huge tails through their poop to drive away or confuse attackers.

As the event unfolded, onlookers noticed a large, "dark bubble" pop up to the water's surface. At first, they thought it was blood from one of the sperm whales, potentially a small calf. But when the team later reviewed footage of the plume, they realized it was actually whale poop.

"Because [a] sperm whale's diet consists mostly of squid, they actually have this really reddish colored poo," she said.

Related: Why some whales go through menopause

In this demonstration of defense defecation, the pod formed a circle with their heads together, and the whales fanned their tails in unison — forcing their excrement toward the unsuspecting orcas.

"This is called a rosette, another defensive mechanism they use when they're under attack," Tucker said.

Tucker told ABC she noticed that the sperm whales looked distressed and exhausted. However, their fecal warfare worked, and the orcas swam off in search of fresher waters. It was in the midst of this mayhem that researchers saw the big, blobby poop bubble rise to the water's surface.

There have been only a few documented instances of orca attacks on sperm whales, largely due to the sheer size differential between the two species.

"Sperm whales are considered an apex predator, and historically, it was thought that they were pretty much immune to killer whale attacks," Tucker said. "It's actually pretty adventurous for orcas to try to take on sperm whales. They're punching above their weight."

Poop, feces, stool — whatever you call it, there's no denying the unpleasant smell. While it's perfectly normal for poo to be pungent, it makes you wonder what it is about our excrement that makes it stink. So why does poop smell bad?

"Stools are generally not a pleasant smell because they are releasing byproducts of your digestion," Shelby Yaceczko, a clinical dietician at UCLA Health, told Live Science.

Skatole, also known as 3-methylindole, is "one of the compounds in feces that gives it its foul smell," Emma Laing, a clinical professor and director of dietetics at the University of Georgia and a spokesperson for the Academy of Nutrition and Dietetics, told Live Science. Bacteria make this compound when they break down the amino acid L-tryptophan in the gastrointestinal tract, she said. (Oddly enough, the same compound in small concentrations gives a pleasant smell to flowers like jasmine, according to the American Chemical Society.)

Related: Why do some men take so long to poop?

There are more than 10,000 microbial species living in humans and more bacterial cells than human ones. These microorganisms are essential to digestion and largely to blame for feces' odor. Different bacteria emit different gases depending on the types of foods and substances they are breaking down, Laing explained; bacteria in the gastrointestinal tract and the mouth contribute to this process, she said.

Because bacteria break down what we eat, factors such as dietary patterns, alcohol intake, dietary supplements and prescription medication can affect the way poop smells. Sugar alcohols, like sorbitol, are often used in candies and can make poop smell particularly bad. And sulfate-containing foods — like eggs, broccoli, cabbage, cauliflower, onions, legumes and meat — can contribute to the production of sulfur gas, which has a rotten egg smell, during digestion.

Highly processed and sugary foods can be difficult to digest, leading bacteria to produce more gases and stinkier poo, Yaceczko said. And consuming large amounts of alcohol produces smelly stools because it wreaks havoc on the intestines and the digestive process, Laing added.

If you notice a change or worsening in the smell of your stool, it's most likely due to a change in your diet or medication, Laing said. The digestive process eventually adjusts, and the worsened smell is usually temporary, she added.

However, an especially foul smell, like a putrid or rotten odor, that doesn't go away could indicate a serious health problem. Malabsorption diseases, like inflammatory bowel disease or celiac disease, can prevent the body from digesting and absorbing nutrients, which can cause consistently foul odors. A viral or bacterial infection in the gut could also be to blame. And so-called motility disorders, which cause a slower-than-normal emptying of the gastrointestinal tract, give poop a longer time to ferment, thus increasing the stink, Yaceczko said.

If an unusually bad smell persists, especially in combination with symptoms such as diarrhea, blood in the stool, abdominal pain or fever, "a prompt visit to your health care provider is warranted," Laing said.

This article is for informational purposes only, and is not meant to offer medical advice.

Everybody poops, but only some of that poop fossilizes, turning into coprolites. While ancient droppings may sound gross — after all, who wants to go digging through feces that are centuries or even millennia old — they can offer a cornucopia of data to scientists.

For instance, coprolites can reveal which foods people ate, the parasites that lived in their guts and even prove that humans lived in an area, like North America during the last ice age, according to coprolites found in a cave in Oregon.

Here are eight times human coprolites dropped knowledge on modern scientists.

Related: 10 amazing things we learned about our human ancestors in 2022

1. Parasites galore

Human poop found in old latrines reveals that gut parasites were rampant in the ancient world. For example, biblical-era toilets in Jerusalem had excrement with protozoa that caused "traveler's diarrhea"; human waste from the Roman Empire had whipworms (Trichuris trichiura), roundworms (Ascaris lumbricoides) and Entamoeba histolytica, which can cause dysentery; and 800-year-old Crusader poop from Cyprus was teeming with whipworms and roundworms.

These unsavory hitchhikers reveal that people in these times likely ate undercooked meat, such as the uncooked and fermented fish sauce known as garum that was popular in Roman times. Or, perhaps these parasites spread through bad sanitation practices, such as contaminated water or a lack of hand washing.

2. Ancient humans in Oregon

For nearly a century, researchers thought that the first humans in the Americas were the Clovis, a group that arrived in North America shortly before 13,000 years ago. But in recent decades, researchers have found evidence indicating that humans arrived thousands of years earlier. One of those findings, of human coprolites in Oregon's Paisley Caves, shows that people were in what is now the United States by 14,500 years ago.

When the study came out in 2012, these fossilized feces were the "oldest directly dated human remains (DNA) in the Western Hemisphere," the researchers wrote in the journal Science.

3. Stonehenge-era builders ate parasite-infested meat

Neolithic construction workers left behind more than just stone structures. At Durrington Walls, a Neolithic settlement about 1.7 miles (2.8 kilometers) from Stonehenge in England, researchers found fossilized clusters of human poop, suggesting that these builders had epic winter feasts in which workers and their dogs chowed down on undercooked meat rife with the eggs of parasitic worms.

"This is the first time intestinal parasites have been recovered from Neolithic Britain, and to find them in the environment of Stonehenge is really something," study lead researcher Piers Mitchell, a biological anthropologist at the University of Cambridge in the U.K., said in a statement.

4. Disappearing high-fiber diets

The Indigenous people of the American Southwest used to eat high-fiber foods such as prickly pear, yucca and flour ground from plant seeds, according to an analysis of fossilized feces from A.D. 1150 and earlier. This diet was 20 to 30 times more fibrous than a typical modern diet, a 2012 study found. The rapid change from high-fiber to low-fiber processed foods prevalent in modern diets may explain why many Indigenous people have type 2 diabetes today.

"When we look at Native American dietary change within the 20th century, the more ancient traditions disappeared," study researcher Karl Reinhard, an environmental archaeologist at the University of Nebraska-Lincoln, previously told Live Science. "They were introduced to a whole new spectrum of foods like fry-bread, which has got a super-high glycemic index."

5. Arctic archipelago poop

Sometimes you don't find a coprolite, but the chemicals leftover from human waste. That was the case for researchers investigating periods of human occupation in the Lofoten Islands, a Norwegian archipelago in the Arctic Circle. The team took several sediment cores so they could look for chemical components of human and livestock waste. They also looked for chemical footprints of burned vegetation.

According to these chemicals, people and animals came to the area around 2,300 years ago and burned vegetation, likely to clear forests to make way for farming and grazing land. But poop output decreased around the time that Iceland was discovered, likely because people decided to migrate there. Poop levels also dropped when plague hit the region. When the Little Ice Age hit (circa 1300 to 1850), poop chemicals stayed constant while burned vegetation signatures increased, likely because settlers were stoking fires to stay warm.

6. Our Mesolithic ancestors were cannibals

In case you needed proof that Middle Stone Age, or Mesolithic humans were cannibals, look no further than their coprolites. Bits of human bones were found in human poop from 9,000 to 10,200 years ago deep in a cave in Alicante, Spain. Some bones had bite, cut and scrape marks, the researchers found. However, it's unknown if these people were eaten during rituals or because the cannibals were starving.

7. People ate cotton

Ancient DNA from 1,500-year-old coprolites in the Caribbean revealed foods favored by pre-Columbian cultures. Two groups in Puerto Rico, the Huecoid and Saladoid, used to eat an array of foods, including maize, sweet potato, chili peppers, peanuts, papaya, tomato and, unexpectedly, cotton and tobacco, according to fecal analyses. It's possible that cotton seeds or oil were consumed, but cotton oils are bitter, according to the researchers, who published their 2023 findings in the journal PLOS One. So another possibility is that Indigenous women who wove with cotton fibers used their saliva to prepare the raw yarn, the team noted.

These cultures may have also chowed down on a "variety of dietary, medicinal, and hallucinogenic plants," the researchers wrote in their 2023 study, published in the journal PLOS One.

8. Ancient hyenas ate humans

Coprolites from ancient hyenas and their bite marks on bones reveal that humans were on the menu for these carnivores up to 4,500 years ago in Saudi Arabia. The hyenas took up residence in a lava-tube cavern for several millennia, leaving behind piles of old bones, including those of humans.

It's unclear if the hyenas had killed or scavenged their human prey. Other bones in the lava tubes included those from donkeys, caprines (a type of goat), gazelles, camels and wolves or dogs.

After you eat beets, you may get a shock when visiting the restroom: Your poop looks slightly pink, or sometimes dark, berry red.

This rather unnerving experience may make you wonder, "why do beets turn your poop red?"

The answer lies in betanin, the reddish-purple pigment that gives red and purple beets their vibrant color, Whitney Linsenmeyer, an assistant professor of nutrition and dietetics at Saint Louis University in Missouri and a spokesperson for the Academy of Nutrition and Dietetics, told Live Science by email. The same pigment is not found in golden beets, which instead contain yellowish pigments called betaxanthins.

Betanin is not only a pigment but also a strong antioxidant, meaning it can neutralize reactive molecules called "free radicals" in the body. By stabilizing free radicals, "it may help prevent damage to DNA and other cells and is also considered to have anti-inflammatory properties," Linsenmeyer said.

Related: Nine benefits of antioxidants: From disease prevention to healthy aging

However, betanin has a low bioavailability, meaning little metabolized betanin enters the bloodstream, so the body can't make full use of the compound. The pigment is highly resistant to digestive processes, and only a fraction of the betanin we consume can get absorbed by the cells in the gut, Linsenmeyer said. Lab-dish and animal studies suggest that roughly half of the ingested betanin gets broken down, mainly in the intestines, according to a 2021 review published in the journal Molecules.

Betanin that is not broken down by the body passes through the digestive tract largely intact. That means it may end up excreted with poop, turning it red or pink as a result. "This is a normal reaction observed in about 1 in 10 people," Linsenmeyer said.

This widely cited statistic likely comes from a 1963 study, which suggested that 10% to 14% of people experience "beeturia," a phenomenon where beets turn your urine red or pink. Beeturia happens when unmetabolized betanin passes through the kidneys and into urine, but it's often accompanied by betanin turning a person's poop reddish, as well. So the two phenomena are closely linked.

"It is considered a benign condition that may persist for a few hours after the meal," Linsenmeyer said of beeturia.

Some studies initially suggested that a person's likelihood of experiencing beeturia might be linked to genetic factors or to iron deficiency, but more recent studies have concluded that the effect is more likely caused by the body's limited ability to metabolize betanin, according to the 2021 review.

"If you notice discolored urine several days later, however, this is not likely caused by eating beets and warrants a call to your doctor," Linsenmeyer said. Urine with a persistent red or pink color can indicate presence of blood, and according to Penn Medicine, bloody urine is a common sign of structural abnormalities or diseases within the urinary tract.

The exact time it takes for beets to turn your poop red can depend on how long it typically takes you to digest food. If you're concerned about your stool turning a reddish color, doctors can test a sample to rule out the presence of blood, and along with that exam, they'll likely ask if you've recently eaten something that might have turned your poop pink, according to the National Library of Medicine's MedlinePlus.

This article is for informational purposes only and is not meant to offer medical advice.

While dogs may be man's best friend, it's hard to avoid judging Fido when he gets into his own feces.

A 2018 study published in the Journal of Veterinary Medicine and Science surveyed about 1,400 dog owners in the United States and found that 23% of dogs had eaten poop at least once and 16% were "frequent" poop eaters who ate poop at least six times over the course of the study.

But why do dogs eat poop, and is it harmful to them?

Dogs eating their own poop — a condition called coprophagia — is considered a natural behavior. It's not a form of attention seeking or a result of nutritional deficiencies. Instead, veterinarians think coprophagia in dogs stems from their evolutionary connection to wolves, as wolf mothers eat their pups' poop to avoid exposing them to intestinal parasites.

Wolves will eat the feces of their young during the first three years of life, veterinarian Dr. Nicholas Dodman, president of the nonprofit Center for Canine Behavior Studies and a professor emeritus at Tufts University Cummings School of Veterinary Medicine, told Live Science. In fresh poop, the eggs of various parasites are not yet infectious. If let to sit, the parasites can grow and infect the pups if ingested.

"You're more likely to survive if you're healthy than if you're … ridden with worms," he said.

Related: Could dogs survive without humans?

Even though domesticated dogs have come a long way from the wolf den, "I think the important takeaway is that it's no risk; it's just disgusting to us because of our upbringing," Dodman said.

Which dogs eat poop?

Certain dog breeds might be more prone to coprophagy, the 2018 study found. Shetland sheepdogs had the highest rate of coprophagia (41%), while no poodles were reported as poop-eating. A dog's sex is also linked to its tendency to eat poop. A 2019 study conducted by Dodman and colleagues and published in the Journal of Veterinary Behavior looked at the behavior of over 4,000 dogs. They found 11% of male dogs engaged in poop eating, while 16% of female dogs did. Interestingly, coprographia was twice as common in dogs that were neutered than in dogs that were not neutered.

As for why dogs eat the poop of other animals, like cats and rabbits … it's just tasty, Melissa Bain, a veterinary behaviorist at UC Davis Veterinary Medicine and co-author of the 2018 study, told Live Science. Cats eat a high-protein diet, so their stool might be particularly delectable to dogs, she said.

How do I get my dog to stop eating poop?

Even if it's not harmful to your pooch, there's no denying that people are repulsed by poop eating. So is there anything you can do to get your dog to stop?

Several commercial products are marketed for getting dogs to stop eating poop, but these have not been proved effective. Bain's 2018 study looked at 11 food additives marketed for coprophagia and found that the effectiveness of these products ranged from zero to 2%. "Don't waste your money," she said.

The internet is full of home remedies to stop coprophagia, like adding breath mints or pineapple to a dog's food. But there's no evidence that this works for most dogs, either. "You'll probably find someone who says they think it worked in their dog," Dodman said. "But basically, it's not a strategy that you can rely on."

In his veterinary practice, Dodman has tried diet changes that alter the consistency of a dog's poop and stop coprophagia. Brands like Hills RD or Purina OM have between about 14% and 16% fiber, according to their websites, which is much higher than in commercial dog kibble, Dodman said. The result is a dog stool that's more like cardboard, he said.

"If you change it to be less palatable, if you can imagine that, and more … dry and cardboardy, that seems to work," Dodman said, although he has not tested this in clinical trials.

What does work? "Clean it up," Bain said, and give the dog no time to munch on its feces. Some owners may try sprinkling Tabasco sauce or cayenne pepper on a dog's poop to deter them from eating it. "But if you're going to do that," Dodman said, "you might as well pick it up."

Viruses scooped from the poop of giraffes, lemurs and long-whiskered mammals called binturongs could be useful for killing drug-resistant bacteria and preventing further antibiotic resistance, scientists say.

Researchers from the University of Sheffield in England have been hunting for bacteria-infecting viruses, known as bacteriophages, in animal feces from Yorkshire Wildlife Park, a wildlife conservation and rehabilitation center in Branton, England. The park houses about 475 animals representing more than 60 species, giving the scientists opportunities to search for bacteriophages — called "phages," for short — in a variety of exotic excrement.

Graham Stafford, chair of microbiology at the University of Sheffield and leader of the research, told Live Science that the idea came to him while he was visiting the wildlife park with his family. When he reached out to the park's staff about the project, "they were keen to help," he said.

Why go digging for phages in animal poop? Phages are the key ingredient in an emerging treatment for bacterial infections, known as phage therapy. In clinical trials and extreme cases where other treatments have failed, doctors have used phages as an alternative or a supplement to traditional antibiotics. Phages typically kill disease-causing bacteria by invading the germs' cells and slicing them open from the inside.

Related: Dangerous 'superbugs' are a growing threat, and antibiotics can't stop their rise. What can?

These phages can have very narrow targets — as few as one or a few bacterial strains within one species — which means they don't pressure a slew of bacteria to resist treatment, as is the case with broader-spectrum antibiotics. Phages do still drive bacterial evolution, but when bacteria evolve to escape phages, the targeted bacteria tend to then become more vulnerable to traditional antibiotics, Stafford said.

Stafford and his colleagues are aiming to discover new phages in the environment — and yes, in animal dung — to add to the variety of phages that can be used in treatments. "They tend to target only certain species, or even certain strains, so the more that we've got … then the more chance we've got of taking this therapy to a point where we can cover as many bases as possible," he told Live Science.

Previously, the researchers isolated phages from human mouths, as they were looking for ones that could treat common bacteria that infect the roots of teeth. In addition, they've looked for phages "in various farm animal effluence," such as that of cattle and chickens, Stafford said. And now, the team has been working with Yorkshire Wildlife Park for a year or so and has gathered phages from Guinea baboons (Papio papio), giraffes (Giraffa), Visayan pigs (Sus cebifrons) and binturongs (Arctictis binturong), as well as various lemurs, according to a statement.

Once the researchers have a poop sample, they add water, blend it into a slurry, and then heavily filter the mixture until only viruses remain. "So now it's a far way from being smelly," Stafford noted.

Then, they expose bacteria in lab dishes to the filtered-out phages, to determine which germs the phages can infect; this reveals which phages would be useful for human treatments. They also extract DNA from the phages, to compare their genetics to those of previously cataloged viruses; test their stability and heat resistance; and take microscopic images to see their shapes and sizes.

The team is currently focused on finding phages that can help treat foot infections in people with diabetes, which is a common complication for those whose blood sugar levels aren't adequately kept in check with medication. Elsewhere in the world, clinical trials are underway or about to begin to test the phage therapies for such infections, and some completed early-stage trials suggest that the treatment is safe in humans.

"It is important not to think that you're going to take poo and put it on people's feet — in the end, you're making a product, like a medicine or an ointment," Stafford said. So, regardless of where the phages in these treatments were originally found, the ones that end up in medicines have been purified, grown in the lab and safely stored under controlled conditions.

Stafford and his colleagues have yet to publish any studies related to their work with the Yorkshire Wildlife Park, but they will likely do so in the coming months, Stafford told Live Science. Meanwhile, they are working toward formulating a cocktail of phages that could be tested as an antibacterial treatment.

_{A slippery new toilet bowl material is resistant to the stickiness of synthetic poop with different moisture contents. (Video credit: Supplementary Materials from Li et al. 2023 DOI:10.1002/adem.202300703)}

An incredibly slippery 3D-printed toilet doesn't get dirty and requires less water to flush than a typical one, scientists say. Could cleaning toilets become a chore of the past?

Right now, the concept is just a prototype, but researchers are working on ways to eventually bring this clever chemistry to market. So far, the researchers have printed only a tiny model of the toilet that stands about one-fifth the height of a typical porcelain throne, and they tested its slickness by exposing its surface to yogurt, honey, starchy gel and fake poop, not the real stuff.

The invention of the flushing toilet revolutionized the way we live, but the innovation came at a cost: namely, 37 billion gallons (141 billion liters) of water flushed per day globally, the researchers wrote in their recent paper, published Aug. 5 in the journal Advanced Engineering Materials. And often, there's another problem: Even all that flushing isn't enough to remove all of the excrement in the bowl.

Bin Su, a principal investigator at Huazhong University of Science and Technology in China, and his team of materials scientists may have found a solution to these problems.

Related: Where does all our poop go?

In their study, the researchers reported that their 3D-printed abrasion-resistant super-slippery flush toilet, or ARSFT, is completely resistant to soiling with various liquids, including milk, muddy water and even synthetic feces. And unlike other slippery toilets, ARSFT maintains its slipperiness even after heavy and repeated use.

The team drew inspiration from tropical pitcher plants (Nepenthes), carnivorous plants that capture prey in vase-like leaf cups; to help channel prey into their traps, the plants secrete a slippery, lubricating substance. Similarly, the researchers coated the toilet's surface in a greasy oil that helped funnel the waste down and out of the bowl.

"When the contaminants fall on to the surface, they first encounter the lubricant film rather than the surface [itself], which can greatly reduce adhesion," the study authors wrote.

On a chemical level, this slippiness originates from a material property called "hydrophobicity," which is a measure of how well the material repels water. Human waste has a high moisture content, so a hydrophobic surface will help prevent poop from sticking.

Using a technique called selective laser sintering 3D printing, the team fused plastic grains and a type of hydrophobic sand to produce the solid shell of the toilet. Sintering is a chemical process that compacts and combines two types of solid without melting them together; importantly, this creates a porous structure with many tiny gaps between the solid particles. The researchers filled these holes using a common lubricating oil that spread throughout the entire structure to coat the whole toilet.

Because the lubricating oil is stored throughout the whole toilet, thanks to the porous structure, any oil lost from the surface is quickly replenished from deeper within the material, enabling the bowl to maintain its super-slippy properties. Even intense mechanical abrasion — like that caused by an overenthusiastic scrub with a toilet brush — doesn't diminish the slipperiness, because the material quickly self-heals by shuffling oil to the newly exposed surface. The team tested this by scrubbing their mini-toilet 1,000 times with sandpaper.

But while the slick new toilet promises to prevent unsightly skid marks on the bowl, it will be a while before you see one of these at your local hardware store.

The team's tiny toilet bowl measured just 3.1 inches (8 centimeters) high, 4.7 inches (12 cm) deep and 3.4 inches (8.8 cm) wide, so it will obviously need to be made bigger. 3D printing can also be notoriously expensive, so producing these toilets cheaply could also be a challenge.

Su's team is already working on these issues. But beyond that, manufacturers would also need to find a way to incorporate the important sintering step into the existing toilet production process. However, there could be uses for this robust nonstick surface beyond toilets, so you may someday see this clever chemistry applied outside the water closet.

For the past 2,200 years, Andean condors (Vultur gryphus), among the largest known flying birds in the world, have been nesting — and pooping — at a cliffside grotto in northern Patagonia, Argentina. Now researchers are studying the massive pile of guano to learn more about the threatened species and how it has adapted to its environment over time. 

To study the doughnut-shaped poop mound, which measures roughly 10 feet (3 meters) in diameter, researchers carved it like a pie, removing a single 10-inch-deep (25 centimeters) slice of excrement. Thanks to the deposit's location inside the grotto, the preserved poo had been well protected from wind and rain, allowing it to amass for thousands of years, according to a study published May 3 in the journal Proceedings of the Royal Society B.

"By looking at the different layers, we could go back in time," lead study author Matthew Duda, a graduate student of biology at Queen's University in Kingston, Ontario, told Live Science. "We carbon dated [the pile] to figure out the nest's age, which is over 2,000 years old."

By examining the preserved poo, the team discovered how the condors' diets had evolved over time.

"Condors are scavengers, and at one time they would fly along the shores and eat carcasses of whales and native species such as llamas and alpacas," Duda said. "But as livestock like sheep and cattle were introduced into South America [by Europeans], their diets changed along with it. We saw a complete shift from before to what is currently most abundant for them to eat."

Related: Critically endangered condor chicks are species' 1st known 'virgin births'

Unfortunately, this shift also meant the condors are ingesting more lead, which Duda attributed to "lead shot being used to kill vermin, which the condors would then eat." These toxic metals were then excreted by the birds.

"We saw that the concentration of lead was significantly higher now than in the past," Duda said.

This is particularly concerning since Andean condors are on the Red List of Threatened Species monitored by the International Union for Conservation of Nature, and their numbers continue to dwindle with only about 6,700 adults still living in the wild.

The researchers also noticed that for one 1,000-year stretch of time, roughly between 650 and 1,650 years ago, the condors more or less abandoned the site, resulting in the guano accumulation dropping drastically from approximately 3 cubic feet (0.08 cubic m) per year to 0.11 cubic feet (0.003 cubic m) per year. They think that increased volcanic activity forced the condors to leave, according to the study.

"We measured an increase in sulfur and sodium, which are both associated with volcanic activity," said Duda, who suspects that as volcanic ash blanketed the surrounding vegetation, herbivores were forced to leave in search of new food resources, causing the condors to take flight too. 

The researchers plan to study other Andean condor deposits in the region to determine "baseline conditions" for the sites, eventually applying their methods to other threatened bird species, including oilbirds (Steatornis caripensis), a nocturnal fruit-eating bird that uses echolocation to navigate.

"It is clear that quality breeding sites are critical for this species' survival," the study authors wrote in their paper. "To support effective conservation efforts, nesting and roosting sites need extensive protection."

It's no secret that invasive rats can cause widespread and long-lasting damage to tropical island ecosystems, but now, a new finding reveals that the invasive rodents' impacts may extend even further than the land on which they scamper; these ravenous critters can also disrupt the surrounding marine ecosystem. 

In the Indian Ocean, invasive island rats have altered the behavior of tiny farming fish known as jewel damselfish (Microspathodon chrysurus) that live on coral reefs located miles offshore, a new study shows. Affected damselfish have become much more docile than normal due to a weird link between the fish and the rats: bird poop. 

Jewel damselfish are normally highly territorial fish that aggressively defend and cultivate small patches of algae that grow on corals surrounding tropical islands. The plant patches are greatly desired by the damselfish because the algae are highly nutritious, thanks largely to the nutrients that run off from the islands. One main source of island-derived nutrients is the poop, or guano, excreted by seabirds that nest on the islands, which then gets washed into the ocean. 

However, invasive rats, which were historically introduced to islands after stowing away on ships, are known to decimate bird populations on their new homes by sneaking into nests and feeding on unhatched eggs. This can cause seabird densities to decrease by up to 720 times on rat-infested islands, which can decrease the nutrients in surrounding waters by up to 251 times, the study authors explained in a statement. As a result, the damselfish's algal patches have become less nutritious, which means the feisty farmers are less inclined to defend them.

Related: Glowing, red-eyed rat fetus is global photo contest's gorgeously creepy winner

In the new study, published Jan. 5 in the journal Nature Ecology & Evolution, researchers compared the damselfish behavior on coral reefs surrounding five rat-free islands and five rat-infested islands in a remote archipelago in the Indian Ocean. 

The team found that damselfish surrounding rat-infested islands had larger territories, measuring an average of 6.7 square feet (0.62 square meter), compared with an average of 5.2 square feet (0.48 square meter) on rat-free islands. The larger territories are a sign that the fish have become less territorial over specific patches, the researchers said.

The team also observed that the fish were up to five times less likely to act aggressively toward one another.

Jewel damselfish around rat-free islands fiercely defend their patch of algal turf because it is packed with  nutrition, which means the fish get "more for their money," by using energy to defend it, said study co-author Rachel Gunn, a behavioral ecologist at Tübingen University in Germany and a former doctoral student at Lancaster University in the U.K. at the time of the study. "We believe that the presence of rats is lowering the nutritional benefit of the turf to the extent that it is almost not worth fighting for, which is what we are observing with these behavior changes." 

The researchers think the change in the damselfish's behavior is likely to have further knock-on effects on their coral reef ecosystems, which have not yet been properly studied.

"The algal farming of damselfish affects the balance of corals and algae on the reef," Gunn said. "Their aggression towards other fish can [also] influence the way those fish move around and use the reef."

The decrease in the available nutrients in the water could also have implications for other algae eaters, as well as for filter-feeding organisms such as sponges, which could, in turn, affect food chains across the reefs, the researchers warned. "Ecosystems evolve a delicate balance over long time scales, so any disruption could have knock-on consequences for the wider ecosystem," Gunn said.

The team believes the new findings show how important it is to control or completely kill off invasive rat populations where possible.

"Rat eradication has the potential to have multiple, cross-ecosystem benefits," Gunn said. The removal of rats from tropical islands would likely restore the territorial behavior of jewel damselfish and provide other benefits to the rest of the coral reef ecosystem, she added.

Everybody poops, but have you ever wondered why, out of all the colors, poop is the color brown? 

While this question might seem like a simple biological curiosity, doctors will likely tell you that the color of your poop is no laughing matter. That's because poop isn't always brown, and when it's not, it can tell you a lot about what's happening inside your body. 

Poop is brown because the body is typically very good at making sure that no useful food goes to, well, waste. Your body breaks down nearly all of the energy sources it can from what you eat, and one of the key substances your body uses to break down and absorb nutrients is bile.

• Related: How much urine can a healthy bladder hold?
• Related: 5 ways your poop can advise you on health
• Related: How much do you poop in your lifetime

While bile itself is yellow-green, its role in digestion leads to the brown color of poop. "Bile plays a vital role in the digestion and absorption of intestinal nutrients such as cholesterol, fat, and fat-soluble vitamins," Dr. David Q.H. Wang, a professor of medicine at Albert Einstein College of Medicine in New York, told Live Science. "Bile contains bilirubin, which is secreted by the liver and stored in the gallbladder. During a meal, bile is released into the small intestine. In the intestine, bilirubin is converted to urobilinogen and then reduced to stercobilinogen. Both urobilinogen and stercobilinogen are colorless. Finally, stercobilinogen is oxidized to stercobilin that is excreted in the feces."

Stercobilin is responsible for the brown color of human feces. "It should be pointed out that human feces are usually light to dark brown in color and are composed of a combination of the bilirubin derivatives, mainly stercobilin and some urobilin," Wang explained. "The longer stercobilin is oxidized, the darker the stool will be. The color of feces also depends on the freshness of the stool, the concentration of stercobilin, and the stercobilin/urobilin ratio."

What does it mean if your poop isn't brown?

Doctors are interested in the color of your poop because discolored stools can be a warning sign of gastroenterological problems. However, not all discolored stools are cause for concern. 

"In some cases, certain foods can change the color of feces," Wang said. "For example, feces can be green due to eating licorice candy, as it is typically made with anise oil rather than licorice herb. Feces may turn black if a certain amount of the food containing animal blood (i.e., pig blood) is consumed." 

These colors, if occasional and tied to a specific food you've just eaten, aren't cause for concern. 

What your poop says about your health

Sometimes, medical conditions can affect how your body processes or absorbs various nutrients, which, in turn, can affect the resulting color.

"Under normal physiological conditions, human feces are light brown to dark brown in color," Wang said. "In some pathological conditions, the color of the stool changes. For example, when any type of bile duct is obstructed [which can occur due to a range of conditions], it usually results in a tarnished silver or aluminum paint-like stool color."

Other colors can also be a sign of illness. "Feces can be black in color because red blood cells stay in the intestine long enough to be broken down by digestive enzymes," Wang said. "This is called melena and is usually due to upper gastrointestinal bleeding, such as bleeding from a peptic ulcer in the duodenum [the uppermost part of the small intestine] and/or stomach." 

In these instances, the color of your poop matters to doctors, because it may indicate that something is wrong in your body.

"If you notice a change in the color of your feces, you have to see your doctor as soon as possible," Wang said. 

• Related: Why is my poop green?

Originally published on Live Science.

The next time you're fidgeting in an uncomfortable seat on a crowded train or airplane and wishing for a better way to travel, be grateful that you aren't a tardigrade. For these near-microscopic animals, getting from one place to another sometimes means being swallowed by a snail, riding in its guts and then exiting the mollusk via the anus, on a clump of feces.

Despite the obvious drawbacks of this arrangement, traveling by snail is certainly faster for a wee tardigrade than walking. Unfortunately, tardigrades have only about a 30% chance of surviving the trip, as they run the risk of being digested along the way, scientists discovered.

Tardigrades, also known as moss piglets or water bears, measure between 0.002 and 0.05 inches (0.05 to 1.2 millimeters) long, and are surprisingly cute for such small organisms, with endearingly tubby bodies, round faces and eight stubby legs. They are found almost everywhere on Earth where there's liquid water, but little is known about how such small creatures reach and populate new environments. Winds and water are thought to be the primary conveyors of microbial life (including tardigrades) from one ecosystem to another, and some research has suggested that larger animals may also play a role, serving as buses and taxis for microscopic stowaways. 

But there was little direct evidence of tardigrade dispersal by way of snail ingestion and defecation — until now, scientists recently reported.

Related: 8 reasons why we love tardigrades 

About two years ago, lead study author Tommi Vuori, a master's student in the Department of Biological and Environmental Science at the University of Jyväskylä in Finland, first considered the notion of animals swallowing and then dispersing tardigrades, he told Live Science in an email. A conversation with his supervisor about living tardigrades found in bird feces, described by researchers in 2020 in the journal Polar Biology, led Vuori to another study published in the Journal of Parasitology in 1962, in which scientists described finding live tardigrades in land snail feces. 

These examples inspired him to seek other instances of tardigrade dispersal by land animals, Vuori said. He decided to look for animals that ate moss, where tardigrades are often found, and with feces that "would be easy to sample."

"That's the point when copse snails (Arianta arbustorum) came to my mind," Vuori said. "Everyone who has done any gardening in Finland knows that those snails eat almost anything." So Vuori and his colleagues sampled feces from 21 copse snails collected from a community garden, brought them into the lab and spent around 30 hours examining them, finding tardigrades from two genuses — Macrobiotus and Hypsibius — in about 25% of the feces, according to the study.

"A total of 10 tardigrades were recovered from wild snail feces of which 5 were alive," the authors reported March 31 in the journal Ecology. Some of the tardigrade survivors even reproduced after their recovery, providing the first evidence of tardigrade reproduction after emerging from an animal's gut.

The researchers then fed other tardigrades to copse snails, finding that 218 of the 694 tardigrades (about 30%) survived the ordeal and were pooped out while still alive; 78 were dead on arrival, and the rest "are supposed to have been digested," the authors wrote.

Tardigrades protect themselves from potentially lethal conditions — such as temperature extremes, ultraviolet radiation, the vacuum of space, quantum entanglement and even being shot out of a high-speed gun — by entering what is known as a tun state, in which they expel moisture from their bodies and slow metabolic processes. But becoming a tun is impossible during a snail journey because the gut interior is exceptionally moist, so a traveling tardigrade would lack the protection that a tun state might offer, the scientists reported. 

Most of the snails carried their water bear passengers for two days before ejecting them by process of elimination. Copse snails can travel a maximum distance of about 13 to 16 feet (4 to 5 meters) per day; that means a tardigrade traveling by a snail could relocate — and reproduce — dozens of feet from where it started, which could help wee water bears establish populations in new territories, the researchers wrote.

"Tardigrades have been previously found alive from the feces of snails and birds, but their reproductive ability after passage through the digestive system has been ignored," Vuori said in the email. Finding that tardigrades can reproduce after passing through the gastrointestinal tract of an animal — in this case, a land snail — is therefore an important discovery, and it hints at the water bears' future success in their new home, according to the study.

"Merely transporting an individual to another location is not sufficient, but reproductive ability is prerequisite for colonizing novel habitats," Vuori said.

Originally published on Live Science.

In a first for paleontology, scientists have found hundreds of tiny, fossilized fecal pellets crammed inside a fish braincase dating to about 9 million years ago. The wee fossil poops, also known as coprolites, were deposited by scavengers — probably worms — that devoured the fish's decaying head, including its brain.

As they munched the flesh from the skull, the worms pooped out chains and clusters of oval coprolite beads, each measuring about 0.1 inches (2.5 millimeters) long. Small as they were, those pellets added up over time. When the hungry scavengers were done, they had left behind hundreds of pellets — enough poop to fill the fish's braincase entirely.

Researchers found the coprolite-filled fossil at Calvert Cliffs, a site in southern Maryland that contains fossils dating from about 18 million to 8 million years ago, during the Miocene epoch. The skull belonged to the fish Astroscopus countermani, a type of bottom-dwelling ambush predator commonly known as a stargazer, and small, oblong coprolite pellets such as these are known collectively as Coprulus oblongus. In addition to the fecal-stuffed skull, the scientists also examined other coprolite pellet deposits that were clustered in sandy sediments, stuck to fossilized snail and bivalve shells, and grouped around preserved barnacles at the site.

Related: 8 bizarre animal surprises from 'true or poo' — can you tell fact from myth?

Another notable fossil in the group was a much larger coprolite measuring 7 inches (18 centimeters) long, that had been pooped by a vertebrate, possibly an ancient crocodilian. Threading through the preserved poop were deep tunnels that had been dug out by unknown animals eating the poop or digging a home — or both, researchers reported in the March 2022 issue of the journal Rivista Italiana di Paleontologia e Stratigrafia (Research in Paleontology and Stratigraphy).

Many Miocene marine creatures have previously been described from Calvert Cliffs fossils, including sharks and other fish, turtles, crocodiles, seabirds and seals, according to the study. A variety of coprolites have also been collected near the cliffs, though microcoprolites that are produced by invertebrates — such as the coprolites in the fish skull — haven't been as well-studied as poop from animals with backbones, according to the study. 

Scientists determined that the tiny beads inside the skull were fecal pellets "on the basis of their very characteristic size, shape and chemical composition," said lead study author Stephen Godfrey, a curator of paleontology at the Calvert Marine Museum in Solomons, Maryland. Nondestructive X-ray spectroscopy revealed that these microcoprolites had relatively high concentrations of calcium and phosphate, which are commonly found in fossilized feces, Godfrey told Live Science in an email. (While there’s no way to tell for sure if the scavengers munched on fish brains, the poop-filled braincase suggests that brains were probably on the dinner menu.) 

But whose poo was it? A dead animal's corpse attracts numerous scavengers, many of which "will be perfectly happy to eat your brains and fill your skull with feces," Godfrey said. Micropellets such as these are produced by insects, worms, sea squirts, snails and clams; but since the coprolites came from a marine environment, "we can safely rule out terrestrial insects as the producers," Godfrey said. Sea squirts could also be ruled out, because they spend most of their adult lives attached to rocks, and acorn worms were also crossed off the list due to their habit of defecating outside their burrows.

Because the fecal pellets were found in the innermost parts of a fish skull that measured no more than 2 inches (5 cm) wide, they were probably pooped out by an invertebrate that could squeeze its soft body into tight spaces. "This would probably then rule out snails and clams, leaving polychaete worms and other kinds of worms as the most likely candidates," Godfrey said in the email. 

The researchers also noticed that all the wee pellets were similar in their size and shape, Godfrey said. In fact, he was "most surprised and actually impressed" by the coprolites' uniformity, compared to the inconsistently shaped fecal output of most vertebrates.

"How and why is it that some worm could produce such uniform and wonderfully-shaped feces is remarkable to me," he said.

Originally published on Live Science.

The thunderous calls of common hippos can be heard from more than half a mile (1 kilometer) away — and when a hippo hears the booming call of an unfamiliar hippo, the animal often responds by letting loose a dramatic spray of dung.      

Hippos (Hippopotamus amphibius) spray dung as a way to mark their territory, but until now, scientists didn't know that an unfamiliar hippo’s call could provoke this behavior in another hippo. In a new study, published Monday (Jan. 24) in the journal Current Biology, researchers observed hippos at the Maputo Special Reserve in Mozambique and found that the animals recognize and respond differently to the calls of different hippos in the area, depending on whether those hippos live in the same territory, a neighboring territory or somewhere farther away.    

Specifically, the hippos could differentiate a familiar hippo from a stranger by the sound of their "wheeze honk," the animals’ signature call.

Related: Gallery: Evolution's most extreme mammals 

"The wheeze honk is recognized as the characteristic call of the hippo, consisting of a higher pitched 'wheeze' followed by several 'honks,'" said Maria Maust-Mohl, an associate professor in the psychology department at Manhattan College in New York City, who studies animal communication and was not involved in the study. That initial "wheeze" swells quickly and loudly, like the sound of a trombone, and the "honks" that follow sound sort of like a deep, throaty laugh.     

Hippos often produce wheeze honks at the same time as others in their social group, as if in chorus, and seem to sound the call in response to changes in their environment, Maust-Mohl told Live Science in an email. For this reason, it's thought that the wheeze honk may be a key element of hippo social communication, Maust-Mohl and her colleagues reported in a 2015 study published in The Journal of the Acoustical Society of America. Now, the new study reveals how wheeze honks may help hippos define their social groups and distinguish friend from foe.

"As a territorial species, it would not be unusual for hippos to have adapted this ability to distinguish and react differently to hippos that may be more familiar versus those that may be more of a threat," Maust-Mohl said. "The findings of this study suggest the wheeze honk may serve to help hippos determine the presence and identity of other hippos nearby, as well as communicate within and between groups in their shared habitats."

But although the study offers new insights, "I think the sample size is a bit small," said Camille Fritsch, a postdoctoral researcher at the University of KwaZulu-Natal in South Africa, who studies hippo behavioral ecology and was not involved in the study. The research could be repeated in larger groups of hippos, in different habitats and at different times of the year, since the distribution of hippos shifts between the wet and dry seasons, he said. "It will definitely lead to further study."

Hippos feed at night, consuming up to 80 pounds (35 kilograms) of grass each evening, and the massive herbivores gather in bodies of water during the day, forming groups that typically consist of a dominant male, a variable number of females and juveniles, and a few peripheral males.

"On the same lake, several groups, or pods, can cohabit," Nicolas Mathevon, a co-senior author of the study and director of the Sensory Neuro-Ethology Team at the University of Saint-Etienne in France, told Live Science in an email. "When we decided to study hippos, a question immediately arose: can they recognize each other by voice?"

To answer this question, the team recorded wheeze honks from seven different groups of hippos living on lakes at the Maputo Special Reserve. The group sizes ranged from three individuals to 22; hippos on the reserve often live in groups of 10 to 25, depending on the area, Miguel Gonçalves, the reserve's park warden, told Live Science in an email.  

With these recordings in hand, the team then set up speakers near each hippo group’s habitat, positioned about 230 to 295 feet (70 to 90 meters) away from the animals, and played back the sounds.

The hippos reacted to the recordings by producing their own wheeze honks, approaching the speakers or marking their territory with feces, or by displaying a mixture of these behaviors — but their responses varied depending on which recording was played, the team found. 

The hippos showed the least reaction to calls from individuals within their group, and reacted slightly more strongly to individuals from neighboring groups at the same lake, the team found. These responses typically only included wheeze-honking and approaching the speaker, and included little to no marking. But the animals consistently showed the strongest reaction to calls from strangers and marked far more often in response to these sounds.

It makes sense that hippos would show less aggression towards hippos they know, Fritsch said. The size of hippos' social groups grow and shrink with the changing seasons; as water resources become scarce in the dry season, small groups of hippos gather at one water source and merge into a single, large group, Fritsch said. "They have some understanding of who's around them. And therefore, it would make sense that they are less aggressive towards those individuals," he said.

It would be interesting to see if and how these social dynamics change over time, as hippo groups move around and their densities thin out or grow more concentrated, he said. It would also be interesting to repeat the experiment with hippos living in different habitats, such as rivers and floodplains, rather than lakes. The new study, although somewhat limited, opens the door to investigate these additional questions, he said.

In the long term, this line of research could help conservationists better protect hippo populations, Mathevon said. For example, in the event that conservationists need to relocate hippos to a new habitat, "it may be possible to get the local hippos used to the voice of the new ones before they arrive, and vice versa," Mathevon said. Of course, hippos may still be provoked by the sight or smell of an unfamiliar hippo, even if they recognize the sound of their voice. But introducing the voice ahead of time may still help, he said. 

Gonçalves agreed that such studies of hippo communication could help inform translocation strategies, should that ever be needed at the reserve. The research could also be useful for estimating hippo population sizes, by someday allowing scientists to estimate the density of a hippo group based on the amount of sound it produces, for instance, he said. 

"Although hippos are not listed as endangered, their populations are declining rapidly," Maust-Mohl said; thankfully, within the confines of the Maputo Special Reserve, estimates suggest that the local hippo population is currently increasing, Gonçalves noted. "Future studies of their behavior and communication can help improve the management and conservation of this species by allowing us to better understand the nature of their social groups," Maust-Mohl said.

Editor's note: This article was updated on Jan. 25 with comments from Park Warden Miguel Gonçalves. The story was first posted on Jan. 24. 

Originally published on Live Science.

Genes passed down by your parents may influence how often you poop, a new study suggests, and these key pooping genes may hold clues as to what causes poorly-understood gastrointestinal disorders, such as irritable bowel syndrome (IBS).

That said, the new research comes with a number of caveats, said Dr. Emeran Mayer, a professor, gastroenterologist and neuroscientist at University of California, Los Angeles, who was not involved in the study. For instance, while this and other studies hint that IBS may have a genetic component, other factors, such as a person's diet and stress levels, likely have a bigger effect on the disorder's symptoms, Mayer told Live Science in an email.

The new study, published Dec. 8 in the journal Cell Genomics, included genetic sequences and health data from 167,875 individuals with records in the U.K. Biobank, a huge biomedical database, and four smaller databases curated by the Netherlands, U.S., Belgium and Sweden. Some of these patients had IBS, which involves intestinal symptoms, such as recurrent abdominal pain, bloating, gas and changes in bowel function, including constipation, diarrhea or both, according to UCSF Health. On top of providing their DNA for analysis, these individuals answered a critical question: "What is the average number of times you open your bowels per day?" In other words, how often do you poop? 

Related: How much do you poop in your lifetime?

Based on the participants' answers and genetic sequences, the team found that how often a person poops shows a "modest but detectable heritability," meaning it's at least partly influenced by genetics. In determining this, they identified 14 stretches of the genome that seemed linked to stool frequency. 

Those who pooped less frequently than other participants showed similar patterns of genetic variation within those 14 areas, and those who pooped more frequently also shared a similar genetic make-up in those gene regions. Overall, most participants reported pooping once, twice or three times a day; fewer people reported four, five or six times, and a smaller group reported huge numbers, up to 20 times a day, D'Amato said. (There's a range for what stool frequency is considered "normal," but 20 times a day would not be normal under any circumstances, he added.)

To see if they could predict which participants experienced IBS based on these distinct genetic profiles, the researchers calculated a "polygenic risk score" for each person. That risk score indicated how likely each participant was to have high stool frequency, based on their genetic make-up. They found that those in the top 1% of scores showed a fivefold higher risk of IBS than the rest of the participants, specifically the subtype of IBS that causes increased diarrhea (IBS-D). 

But why would that be? To start to answer that question, the team looked more closely at which specific genes appeared in the 14 stretches of DNA and how they may relate to defecation and IBS. 

Each of these regions of DNA contains several genes, and in looking at the genes with known functions, "some of them made a lot of sense," said senior author Mauro D'Amato, formerly head of the Gastrointestinal Genetics Lab at CIC bioGUNE, a health science research center in Spain, and now a professor of medical genetics at the Libera Universita' del Mediterraneo in Italy.

For example, one gene codes for brain-derived neurotrophic factor (BDNF), a protein that helps direct the function and survival of nerve cells throughout the body. Evidence suggests that increasing the level of BDNF in the gut can boost motility — or how quickly material moves through the gastrointestinal tract. In the past, it's been tested as a potential treatment for chronic constipation, according to a 2000 report in the journal Gastroenterology. 

Seeing the BDNF gene pop up in the new study hinted to the authors that they were on the right track, D'Amato said. At the moment, it's unclear exactly how different versions of the BDNF gene might influence stool frequency, but it gives the team a good starting point for future research.

Related: Genetics by the numbers: 10 tantalizing tales

A few other interesting genes cropped up in their analysis, including some that code for neurotransmitters, hormones and other molecules that help control the nerve cells involved in intestinal peristalsis, the wave-like movements that push poop through the intestine. Many of these molecules also play roles in the brain. 

This finding may somewhat align with an earlier study by D'Amato and his colleagues, published Nov. 5 in the journal Nature Genetics, which hints that the genetic risk factors for IBS overlap with those for anxiety and depression. This genetic data also coincides with clinical observations of IBS patients, who often experience elevated anxiety levels prior to their IBS symptoms. Research has started to suggest that IBS involves both the brain and gut, rather than the gut in isolation, Mayer said.  

Looking forward, D'Amato and his colleagues plan to study in more detail each stretch of DNA identified, nailing down which genes are most important to stool frequency and to the symptoms of IBS. They also hope to address some of the limitations of the current study, including the fact they didn't have any data on participants' diets, which would obviously influence both their stool frequency and potential IBS symptoms.

Another limitation is that study participants were asked how many times they poop each day, rather than each week or month. "So we are missing those people who may have, you know, one bowel movement per week," D'Amato said. "Because of the way the question was posed to the participants, you're sort of looking at the right half of the spectrum." For this reason, the current study is more useful for investigating IBS-D, and more data will need to be gathered to perform a similar study of IBS with constipation (IBS-C), he said.

But even if the team can get better stool frequency data, it's unclear whether a person's self-reported bowel habits really reflect their overall gut motility and all the factors that affect it, Mayer said. Some IBS patients' bowel habits switch from diarrhea to constipation without apparent cause, and it's unlikely that an average measure of stool frequency would capture that. 

Despite its limitations, the current study could help scientists uncover the molecular underpinnings of IBS and eventually come up with new pharmacological treatments for the disorder, D'Amato said. 

But for now, "patients should be aware that even though genetics may play a very small role in the overall disorder, there are many behavioral and lifestyle factors that are more important and that can be modified," Mayer said. Namely, dietary changes, therapies to help with stress reduction and drugs that relieve the intestinal symptoms can all be very helpful to IBS patients, he said. 

Originally published on Live Science. 

Earth's largest animals may eat even more gargantuan amounts of food than scientists thought, a new study reveals. 

Baleen whales — which capture krill, fish, zooplankton and squid by filtering seawater through their special structures in their mouths — may consume up to three times more prey than previously estimated, the study found. 

The discovery could rattle our understanding of how nutrients flow through ocean food webs. After feeding deep underwater, the whales swim upward to breathe and release impressive plumes of poop near the surface of the ocean. There, the iron-rich whale feces acts as a fertilizer for phytoplankton, microscopic organisms that draw energy from sunlight to conduct photosynthesis. The fertilized phytoplankton then get devoured by hungry krill, which then get eaten by whales, and so on. 

Related: In photos: Tracking humpback whales 

If you remove whales from this loop, the iron that would normally be distributed in their poop would instead settle to the ocean floor in krill feces and dead krill carcasses; in turn, this would deprive phytoplankton on the surface of the iron they need to thrive. This may help to explain why, after whalers killed off millions of baleen whales in the 20th century, krill populations within the whaling grounds declined dramatically, falling more than 80% in parts of the Southern Ocean, for example, the study authors wrote in the study, published Nov. 3 in the journal Nature.

"These animals are more important ecosystem engineers than we previously thought," in that they help boost the amount of fuel available to the entire ecosystem, said first author Matthew Savoca, a National Science Foundation postdoctoral research fellow at Stanford University's Hopkins Marine Station. By helping to conserve baleen whale populations today, we could help to restore the iron-recycling system once derailed by industrial whaling, he said.

Big eaters 

Baleen whales get their name from the comb-like structures that grow from their upper jaws. The whales use these structures, made of keratin — the same protein that makes up human hair and fingernails — to filter-feed, either continuously, by swimming open-mouthed through dense throngs of prey, or sporadically, by suddenly lunging at their prey while taking in gigantic gulps of water. Right whales and bowhead whales take the former approach, while blue, fin, minke and humpback whales use the latter.

Although scientists understand the basics of how baleen whales feed, estimating how much they eat has been difficult. Prior to the new study, Savoca was interested in how much plastic and other pollutants baleen whales might be ingesting. But to investigate that question, he had to dig into past research of how much prey the whales consume.

"To my great surprise … it had never been measured in living whales," Savoca told Live Science. In the past, scientists examined the stomach contents of dead whales to get an idea of how much they ate, but such studies couldn't say how much a given whale ate in a day, month or year. Researchers also developed models of how much food a whale would need to survive, but these models were based on the metabolic rates of other large marine animals, such as captive dolphins. 

Given the lack of research on live baleen whales' feeding habits, Savoca and his collaborators decided to gather data straight from the whale's mouth (so to speak). "What these authors did is, they actually measured the amount of food eaten by the whales, by monitoring their feeding behavior," said Victor Smetacek, a professor at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Germany who was not involved in the study.

Between 2010 and 2019, the team placed tags on 321 individual whales from seven baleen species, which lived in the Atlantic, Pacific and Southern oceans. Each tag, secured with a suction cup, was equipped with GPS, a camera, a microphone and an accelerometer, which recorded the whales' movements for about 5 to 20 hours, until the tag popped off. 

Related: 15 of the largest animals of their kind on Earth

The tags tracked how each whale moved in 3D space and therefore revealed when they engaged in feeding behaviors, Savoca explained. The team also snapped drone photos of 105 whales, to determine their lengths, their body mass and the amount of water they could likely capture in one mouthful. To figure out how much prey might be in that mouthful of water, the team visited whale feeding sites in boats equipped with so-called echo sounders. Using sound waves, the echo sounders measured the size and density of groups of prey in the whales' feeding grounds. 

With the tag recordings, drone photos and echo-sounder data in hand, the team could determine how much each whale ate in a day. An adult eastern North Pacific blue whale (Balaenoptera musculus) eats about 17.6 tons (16 metric tons) of krill per foraging day, for example, while the bowhead whale (Balaena mysticetus) eats about 6.6 tons (6 metric tons) of zooplankton. Baleen whales feed an estimated 80 to 150 days out of the year, so using these daily intake estimates, the team could get an idea of how much the whales put away in a single feeding season, Savoca said.

They found, overall, baleen whales eat much more than previous estimates suggested. For example, researchers thought that the krill-feeding baleen whales living in the California Current Ecosystem, between British Columbia and Mexico, gobble up about 2.2 million tons (2 million metric tons) of prey each year, but in actuality, these whales eat closer to 6.6 million tons (6 million metric tons) of prey annually.

"A hopeful story" 

Having determined how much modern-day whales eat, the team wondered how much whales ate in the past, before industrial whaling severely depleted their numbers.

They used whaling industry records to address this question, and focused specifically on Southern Ocean lunge-feeding species, which again nab prey by suddenly charging at them. An estimated 1.5 million of the 2 million lunge-feeding whales killed in the 20th century were removed from the Southern Ocean, with the largest whales, like the blue whale, enduring the greatest losses, the authors noted. 

The analysis suggests that, at the start of the 20th century, minke, humpback, fin and blue whales in the Southern Ocean likely consumed about 473.9 million tons (430 million metric tons) of krill each year. The loss of millions of whales between 1910 and 1970 likely contributed to the subsequent decline in krill, since the whales' poop once fertilized a major food source for the crustaceans, the authors suggest. 

"What it implies is that these historic ecosystems … were 10-fold more productive than they are today," based on the amount of iron-rich poop whales would have produced prior to industrial whaling, Savoca said. And on top of the loss of the whales, climate change likely also drove the decline in krill, he noted. But by both conserving whale populations and addressing climate change, we could potentially regain some of the lost productivity in these ecosystems.  

"I really do think there's a hopeful story here," he told Live Science. All the components of the system — the whales, krill and phytoplankton — are still there, albeit in smaller numbers. What the system really needs is a "jump start," Savoca said. 

Jump-starting the system would involve boosting whale populations through a combination of passive conservation efforts, such as establishing new marine protected areas, and active conservation efforts, such as setting ship speed limits to prevent whales from being struck by boats. Regulations could also bar fishing boats from working when whales are in the area, to avoid entangling the animals in nets. And of course, in addition to these direct measures, broader efforts to rein in climate change would also help whales recover, Savoca said.

In theory, Smetacek said, scientists could jump-start the whale-krill system in another way: By purposefully fertilizing phytoplankton with iron, thus boosting the organisms' growth and, in turn, bolstering krill and whale populations. Essentially, the iron fertilizer would stand in for the missing whale poop.

This idea of seeding the oceans with iron has been raised in the past, as a way to increase the amount of carbon that phytoplankton pull from the atmosphere, Mongabay reported. But the idea remains controversial, in part due to a lack of studies on the potential large-scale ecosystem impacts that such fertilization might trigger. It's also not clear if the effort would boost fish and krill populations in the long term.

Originally published on Live Science. 

Pikas living at high altitudes in Asia eat yak poop to help them survive winter, a new study has found. 

The small, rabbit-like animals, often compared to Pokémon’s Pikachu character, can't hibernate through winter when food is scarce, so they slow their metabolism and eat yak poop to get by on the Qinghai-Tibetan Plateau, where temperatures fall to minus 22 degrees Fahrenheit (minus 30 degrees Celsius). 

Animals adopt all sorts of unexpected strategies to survive, study first author John Speakman, a biology professor at the University of Aberdeen in Scotland and the Chinese Academy of Sciences in China, told Live Science in an email.

"Lots of animals including rabbits and pika eat their own feces," Speakman said. Such poop eating, or coprophagy, can help animals absorb nutrients they couldn't digest initially from their food, Live Science previously reported. "But eating the feces of other species is relatively rare," he added. 

Related: Photos of the pika, North America's cutest mammal

Pikas are a group of small mammals found in North America and Asia. They are often associated with Pikachu the Pokémon which has a similar name — although Pikachu's original design was actually inspired by a squirrel, according to the video game website Kotaku. 

Plateau pikas (Ochotona curzoniae) live in high-altitude meadows up to about 16,400 feet (5,000 meters) above sea level. They don't hibernate or migrate to warmer climates during winter, so exactly how they survive the cold months had remained a mystery. 

To answer this question, Speakman and his colleagues monitored plateau pikas for 13 years using various techniques such as filming the adorable creatures and implanting temperature-logging devices into the animals. Their findings were published Monday (July 19) in the journal Proceedings of the National Academy of Sciences.

To save energy, the pikas reduced their body temperature and limited physical activity such as foraging. At some of the study sites, pikas also ate the feces of domestic yak (Bos grunniens), a phenomenon the team captured on film. 

Yaks are abundant on some parts of the plateau and their feces are likely easily digestible for pikas, having already passed through the yak's digestive system. Munching on yak poop may help pikas spend less energy than they would foraging for other food sources, according to the study. The dung may also contain otherwise scarce nutrients and water, which pikas also benefit from.

Pikas' penchant for yak feces may also explain why they are found in higher densities where yaks are more abundant, even though scientists think the two species compete with one another for food. 

"We are currently studying what other benefits might accrue," Speakman said. "There are obvious potential costs as well, like exposure to gut parasites, so that's probably why it isn't a very common behavior."

Originally published on Live Science.

Sea cucumbers — those chubby tubes of flesh that scooch around the ocean floor — have a very special talent: The tubular creatures are elite poopers, collectively expelling more than 70,000 tons (64,000 metric tons) of sandy poop out of their bottoms each year.

That's not an estimate for the entire globe; that's how much sea cucumbers poop on a single coral reef, per year. And even that tremendous number may be an underestimate, according to a new study, published Feb. 2 in the journal Coral Reefs. 

In the study, scientists studied sea cucumbers living on Heron Island Reef, a 7.3-square-mile (19 square kilometers) reef with a lagoon at its center, located at the southern end of Australia's Great Barrier Reef. The team used drones to collect video footage around the edge of the lagoon, in shallow areas of the reef known as flats, and then counted the sea cucumbers caught on camera. 

From these samples, they extrapolated that more than 3 million cucumbers live across all the reef flats of Heron Island.

Related: Watch this giant sea cucumber expel a spiraling poop log 

Back in the lab, the team ran feeding experiments with the most abundant of the cucumber species, the black sea cucumber or lollyfish (Holothuria atra). They found that a single sea cucumber defecates about 1.3 ounces (38 grams) of poop per day, and would therefore produce about 30.8 pounds (14 kilograms) of poop per year. 

So altogether, the army of 3 million squidgy sea cucumbers living on Heron Island reef produce tens of thousands of tons of poop each year, slightly more than the mass of five Eiffel Towers, the authors wrote. 

Even "this was a huge underestimate of poop, because we didn't include the reef lagoon," study author Vincent Raoult, a marine ecologist at the University of Newcastle, said in a tweet. "Imagine on a global scale" just how much poop sea cucumbers dump into their local ecosystems, he added.

Why should we care about sea cucumber poop? Their droppings are critical to the health of ocean ecosystems, particularly coral reefs.

Related: Survival of the grossest: 8 disgusting animal behaviors

Like underwater earthworms, sea cucumbers gobble up organic matter on the ocean floor, including tiny pieces of algae and marine creatures, Live Science previously reported. The digestion process breaks down this matter, releasing beneficial byproducts that get pooped out along with any indigestible sand that the cucumbers consume. 

These byproducts include calcium carbonate, a key ingredient in coral formation, and ammonia, which acts as a fertilizer and promotes coral growth. Sea cucumber poop is also slightly basic, meaning it lowers the acidity of the surrounding water; less acidic conditions also help coral form their calcium carbonate skeletons, Live Science previously reported. 

"Sea cucumbers turn over sediment, which can aerate the sediment and release nutrients (food) to other organisms on coral reefs," study author Jane Williamson, a marine ecologist and fisheries biologist at Macquarie University in Sydney, told Live Science in an email. If sea cucumbers didn't swallow and poop out the sediment, "these nutrients remain trapped and useless to other animals and plants."

Despite their important role in reef ecosystems, overfishing threatens sea cucumber populations worldwide. Currently, seven species are endangered and nine are "vulnerable to extinction," according to a statement from the University of Newcastle. "The reduction in density means that less sediment is turned over," Williamson said. In other words, fewer sea cucumbers mean less sea cucumber poop, which poses a potential threat to coral reefs.

In sharing their new research, the team has found that "people love the idea that poop is important," Williamson noted. "Everyone poops, so I guess it's something that people can relate to?" she said. 

Originally published on Live Science. 

For some cancer patients, a "poop transplant" could boost the positive effects of immunotherapy, a treatment designed to rally the immune system against cancer cells. 

Not all cancer patients respond to immunotherapy drugs. For example, only about 40% of patients with advanced melanoma, a type of skin cancer, reap long-term benefit from the drugs, according to recent estimates. In trying to pinpoint the differences between patients who respond well to immunotherapy and those who don't, scientists have zeroed in on a likely suspect: the microorganisms living in their guts. 

Now, a new study, published Feb. 4 in the journal Science, adds to the growing evidence that having the right gut bugs can improve a patient's response to immunotherapy, helping to stop disease progression or even shrink tumors. 

In the study, scientists collected stool from melanoma patients who responded well to immunotherapy and then transplanted their feces (and microbes) into the guts of 15 patients who had never previously responded to the drugs. After the transplant, six of the 15 patients responded to immunotherapy for the first time, showing either tumor reduction or disease stabilization that lasted more than a year.

Related: 7 odd things that raise your risk of cancer (and 1 that doesn't)  

"The microbes really appear to drive the immunological … changes we see in patients," said study author Dr. Hassane Zarour, a cancer immunologist, co-leader of the Cancer Immunology and Immunotherapy Program at University of Pittsburgh Medical Center Hillman and a professor of medicine at the University of Pittsburgh. The team linked the changes in gut bugs to changes in both tumor growth and the immune system; for instance, some of the participants showed an increase in specific immune cells and antibodies that appeared in their blood.

Despite the positive changes seen in some patients, fecal transplants likely won't help all patients whose cancer resists immunotherapy, Zarour said. In the new study, for instance, nine of the 15 patients did not benefit from the treatment. As part of their research, the team began to sift through the differences between those who improved after the transplant and those who didn't.

Gut bugs as cancer treatment  

The idea for combining fecal transplants with immunotherapy first came from studies in mice with tumors, in which the rodents responded differently to the drugs depending on which gut microbes they carried, according to Science Magazine. By tweaking the mice's gut microbiomes — the collection of bacteria, viruses and other microbes in their digestive tracts — scientists found that they could improve this response, but they weren't sure which microbes made the difference.

That said, mice's responses to immunotherapy improved after they were given fecal matter from human cancer patients whose tumors had shrunk under immunotherapy. "When they took non-responding mice and gave them the right bugs … they could convert non-responding mice into responding mice," Zarour said.

Other research showed that when human patients took antibiotics, which alter the gut microbiome, they were less likely to respond to immunotherapy, providing more evidence that gut bugs make a big difference in people, too. 

Having seen the positive effects of fecal transplants in mice, scientists began testing the treatment in humans, starting with a few small clinical trials. 

In two such trials, led by researchers at Sheba Medical Center in Ramat Gan, Israel, patients received both fecal transplants and oral pills containing dried stool. The patients then took immunotherapy drugs called "checkpoint blockades," which essentially rip the brakes off of immune cells and help amplify their activity against tumors. A subset of these patients, who had previously not responded to the drugs, suddenly began responding.

The new study by Zarour and his colleagues echoes these positive results, but it also starts to address a crucial question: How do gut bugs boost the effects of immunotherapy?

To answer this question, the team closely analyzed the microbes present in the donor stool samples and the recipients, before and after fecal transplants. The team also collected blood and tumor cell samples to assess the patients' immune responses over time, and computed tomography (CT) scans, to track tumor growth. They then used artificial intelligence to find connections between all these data points. 

Out of the 15 patients, nine still didn't respond to immunotherapy after their transplant. But of the six who did respond, one showed a complete response to checkpoint blockade drugs, meaning their tumors shrunk so much they were no longer detectable; two others showed a partial response, meaning their tumors shrunk but did not disappear, and three have shown no disease progression for over a year. In all six of these patients, the microbes from the donor's stool quickly colonized their guts, and several of the newcomer bugs that were previously  linked to positive immunotherapy outcomes increased in number. 

Related: 11 surprising facts about your immune system

This change in gut bacteria triggered an immune response in the six patients, as their bodies began building antibodies that recognized the new bugs; these antibodies showed up in their blood. While the link between bacteria-specific antibodies and cancer is not well understood, it's thought that some of these antibodies can help prime the immune system to hunt down tumor cells, Zarour said.  

"The bugs that increased in the responders were really correlated with positive immunological changes," he said. These patients also built up a larger arsenal of activated T cells — immune cells that can target and kill cancer cells — while substances that suppress the immune system  decreased. For example, a protein called interleukin-8 (IL-8) can summon immunosuppressive cells to tumor sites and therefore blunt the effects of immunotherapy; but IL-8 decreased in the six responsive patients. 

Links between the gut and immune system 

By comparison, cells that secrete IL-8 increased in the nine patients who didn't respond to the fecal transplant. Based on this new data, "IL-8 seems to really play a critical role in regulating patients' responses" to the two-part treatment, Zarour said. 

Compared with the six responsive patients, the nine others also showed less pronounced immune responses to the transplant and lower levels of the noted beneficial bacteria; some even had dissimilar gut microbiomes to their fecal donors, suggesting the bacteria didn't take over their guts as seen in responsive patients.

In general, "the gut microbiome may be just one of the many reasons we don't respond to a specific treatment," Zarour said, so fecal transplants wouldn't be expected to work for everyone. That said, the immune changes seen in the six responders, including the decline in IL-8, provide hints as to why it works for some people. 

In the future, these results will need to be validated in larger groups of melanoma patients, as well as other cancer patients whose disease resists immunotherapy, Zarour said.

Though small, the new trial provides "firm evidence that manipulating the microbiome can yield benefit when added to immunotherapy for cancer," said Dr. Jeffrey Weber, a medical oncologist and co-director of the Melanoma Research Program at New York University Langone Health, who was not involved in the research. Assuming these results hold up in other patients, though, fecal transplants may not be the best way to deliver helpful microbes into the gut, Weber said in an email.

The future may lie in ingesting the bacteria orally, after they've been freeze-dried, Weber said. This approach could include something similar to the oral pills used in other trials, for example. Either that, or scientists could isolate specific metabolites produced by the helpful bacteria and use those as drugs, Weber said. "The big question is, what metabolites from the 'favorable' bacterial species are actually responsible for benefit," he said. 

Originally published on Live Science. 

When nature calls, wombats poop out a masterpiece — a pile of cubed-shaped BMs, the only animal known to do so. And now, scientists may finally know how wombats pull off this feat, according to a new study published online Thursday (Jan. 28) in the aptly named journal Soft Matter. 

The wombat, a small, tunneling marsupial that lives Down Under, has block-like poops because of the shape of its intestines, the international team of researchers found.

Previously, some researchers had incorrectly proposed that the shape of the wombat's anal sphincter led to the animal's distinctive droppings, much like how Play-Doh can emerge in different shapes when its pushed through different extruders. Even unpublished research presented by the same team at the American Physical Society Division of Fluid Dynamics conference in 2018 didn't quite pinpoint the exact regions of the intestine responsible for the box-like dung, even though it won an Ig Nobel prize in 2019.

Related: Marsupial gallery: A pouchful of cute 

But now, after studying wombat intestinal tissues, examining a CT (computed tomography) scan of a live bare-nosed wombat (Vombatus ursinus) and harnessing mathematical models, the team learned that the poop's cubic geometry likely originates in the last 17% of the wombat's intestinal tract. The wombat intestine is long, about 32 feet (10 meters), or about 10 times the length of its body. But four places — two that are stiffer and two that are more flexible than the rest of the intestine due to changes in muscle thickness — are key for forming the cubic excrements, the researchers found. 

It's likely that these areas of varying muscle thickness help shape the cubes' sharp corners as the intestine undergoes rhythmical contractions, the researchers said. "The corners arise from faster contraction in the stiff regions and relatively slower movement in the center of the soft regions," the researchers wrote in the study. 

Moisture, or lack thereof, also plays a role. Unlike humans, whose digestive process takes one to two days, a wombat's takes as much as four times longer, allowing the marsupial to extract the utmost nutrition. The wombat's intestines are also excellent at extracting water, which explains why their poop is one-third drier than humans. This drying process, which largely happens in the last part of the colon, known as the distal colon, probably helps the wombat keep its poop in a dice-like shape.

The idea for the study began when study co-researcher Scott Carver, a wildlife ecologist at the University of Tasmania, was dissecting a wombat cadaver during a research project on treating mange, a skin disease caused by parasitic mites. It was known that "they place these feces at prominent points in their home range, such as around a rock or a log, to communicate with each other," Carver said in a statement. But it wasn't clear how they made these cubic droppings.

That mystery, now solved, might help scientists assess wombat health. "Sometimes [captive wombat] feces aren’t as cubic as the [wild] ones," study co-researcher David Hu, a biomechanics researcher at the Georgia Institute of Technology, told Science magazine. In other words, wombats with squarer poops might have healthier guts.

In addition, "These results may have applications in manufacturing, clinical pathology and digestive health," the researchers wrote in the study.

Originally published on Live Science.

Giant hornets such as the enormous "murder hornet" and others in the Vespa genus, are highly aggressive and deadly beehive invaders. However, Asian honey bees can defend themselves against these insect predators by smearing animal feces around the hive entrance.

When giant hornets target a beehive, they attack as a group and overwhelm the colony. But Asian honey bees (Apis cerana) that are under attack by the giant hornet Vespa soror, a close relative of the murder hornet Vespa mandarinia, can often prevent hornet attacks by collecting and applying animal waste to their doorways, new research finds.

This poop defense is "next level" for honey bees, which typically rely exclusively on plants for everything they need to survive, said Heather Mattila, an associate professor in the Department of Biological Sciences at Wellesley College in Wellesley, Massachusetts, and lead author of a new study on this unusual bee behavior.

Related: Photos: Murder hornets will haunt your nightmares

"This dung defense is pretty sophisticated; it takes multiple workers to execute it," Mattila told Live Science.

Asian honey bees, which are about 0.4 inches (10 millimeters) long, are dwarfed by giant hornets; V. soror workers measure up to 1.4 inches (35 mm) in length. Like their murder hornet cousins, V. soror hornets are also orange-and-black striped with orange heads, and they share their cousins' bee-killing habits. Giant hornets usually hunt individual bees, but at the end of their breeding season — when the hornet brood is at its most numerous and there are lots of hungry mouths to feed — worker hornets start attacking beehives as a group, Mattila said.

As the study authors observed hornet behavior at apiaries in Vietnam, they saw worker hornets rubbing their abdomens on the bees' hives "and on trees above the hives," Mattila said. "The presumption is that the [hornet] nestmates are following a chemical trail."

If a hornet army followed that scent to a beehive, the carnage was swift and terrible. Adult bees were slaughtered, and any survivors abandoned the hive, leaving their helpless young behind as an all-you-can-eat takeout buffet for the hornets to ferry back to their hungry hornet youngsters, Mattila said.

But Asian honey bees have a few defenses against these giant predators. They can deter hornets by hissing at them, or by gathering in a group and threateningly waggling their abdomens. Bees can also kill a hornet collectively as a "bee ball," mobbing an invader until it suffocates or is cooked to death by the bees' body heat. Asian honey bees are also very quick fliers — "they zig and they zag all over the place" — which helps them evade capture by the slower hornets, Mattila said.

And now, scientists have discovered one more defense — animal poop.

Solid evidence

For the study, Mattila and her colleagues observed apiaries in Vietnam, and of 67 beekeepers who raised Asian honey bees in wooden hives, 94% said that most of those hives had fecal spotting near the entrance. 

The researchers saw that if a hive was visited by giant hornets, the bees responded by collecting bits of solid waste from nearby chicken coops and mammal dung piles and returning with the clumps to the hive. They then applied the dung in tiny mounds that they shaped with their mandibles. 

The poop defense was a solid one. Hives with lots of fecal spotting had fewer visits from giant hornets, which seemed unwilling to chew on or rub up against poop-covered entrances. Hives that the bees anointed with poop were never successfully overrun by giant hornets, according to the study.

"The only time we saw it get to the point where a colony absconded — which is what you call it when they abandon their home — was when we really made it hard for them to defend themselves and opened the entrance so the hornets could get in," Mattila said. The bees then formed "bee balls" that killed some of the invaders, but ultimately the bees abandoned their home because "they couldn't stop the attack," Mattila said.

Anecdotal reports that the researchers collected from Bhutan, southeastern China, Nepal, Thailand and Vietnam described fecal spotting on beehives; as these locations are also within the range of V. mandarinia, it's likely that bees use the spotting defense against mass attacks by murder hornets too, the researchers wrote.

One missing puzzle piece is the fecal ingredient that deters giant hornet attacks. It could be that the waste odor is simply very unpleasant to hornets, or that it masks the chemical scent that they use to "tag" the hive for their nestmates, Mattila said.

"We have a lot of ideas still to explore — it's a pretty big open question at this point," she added.

The findings were published online Dec. 9 in the journal PLOS One.

It seems only fitting that 2020 would be the year when we learn that giant pandas, arguably the cutest of all bears, enthusiastically roll in horse manure — the fresher the better — leaving their entire bodies liberally covered in fresh feces. 

But the pandas are doing it for a good reason; these poo "baths" may help the bears keep warm in their mountain habitat, scientists recently discovered.

Researchers observed this stinky habit in wild Qinling giant pandas (Ailuropoda melanoleuca qinlingensis), a subspecies that lives in the Qinling Mountains in China's Shaanxi Province. The pandas sniffed and wallowed in piles of fresh horse dung, and the frequency of their poop parties typically peaked when temperatures were low, according to a new study.

Related: In photos: The life of a giant panda

In 10 years of observing the Qinling pandas in the wild, scientists began to notice that the bears would frequently display certain behaviors when they encountered fresh horse dung. They would sniff the manure; rub against the manure with their cheeks; roll in the manure; and finally smear the manure over their bodies.

To better understand what the pandas were doing, the researchers installed 24 infrared camera traps in a protected area of the Qinling Mountains where more than 20 pandas lived, recording 38 instances of pandas' poo parties between July 2016 and June 2017. 

"We were surprised to find that the captured events occurred in certain months but not the whole year, implying a pattern of seasonal behavior," they wrote in the study, published Dec. 7 in the journal Proceedings of the National Academy of Sciences.

Poop rolling happened most often between November and April, and about 95% of the feces festivities happened when temperatures were below 59 degrees Fahrenheit (15 degrees Celsius). No poop-rolling occurred when temperatures were higher than 68 F (20 C), according to the study.

But what could explain the pandas' fecal attraction? The scientists suspected that it might have something to do with two compounds that are plentiful in fresh horse manure — which the pandas preferred — but are scarce in older dung: beta-caryophyllene (BCP) and caryophyllene oxide (BCPO). To confirm this preference, the researchers tested captive pandas in the Beijing Zoo using artificial dunghills made of hay, and the captive pandas "frequently visited" the dunghills treated liberally with BCP and BCPO, but showed little interest in dunghills that weren't saturated with the compounds.

Because the panda's poo-rolling was seasonal, the scientists questioned if temperature might be a factor, and they found that mice treated with BCP and BCPO were less susceptible to cold. It's possible that the nerve endings in pandas' skin contain receptors for the compounds; rolling in poo would then temporarily make the pandas less sensitive to winter's chill, the researchers reported.

Wild pandas may have been introduced to this unexpected benefit by ancient trade routes in China that bisected their mountain habitats during the fourth century B.C., the scientists wrote. With horses a constant presence on the road from the Kingdom of Shu (in what is now Sichuan Province) to the capital city of Chang'an (known today as Xi'an, the capital of Shaanxi Province), pandas would have acclimated over time to the scent of horse manure, leading them to investigate and eventually discover a smelly reward for their curiosity, according to the study.

Originally published on Live Science.

In the early days of the COVID-19 pandemic, toilet paper was nearly as hard to come by as personal protective equipment. Though toilet paper has existed in the Western world since at least the 16th century A.D. and in China since the second century B.C., billions of people don’t use toilet paper even today. In earlier times, toilet paper was even more scarce.

So what did ancient humans use to wipe after going to the bathroom?

It can be difficult to tell using the archaeological record, said Susan Morrison, a medieval literature professor at Texas State University and author of the book "Excrement in the Middle Ages; Sacred Filth and Chaucer’s Fecopoetics" (Palgrave Macmillan, 2008). "Most of the material we don't have because it's organic and just disappeared," Morrison told Live Science. However, experts have been able to recover some samples — including some with traces of feces — and depictions of toilet paper’s precursors in art and literature.

Related: Why do some men take so long to poop?

Throughout history, people have used everything from their own hands to corn cobs to snow to clean up after bowel movements. One of the oldest materials on record for this purpose is the hygiene stick, dating back to China 2,000 years ago, according to a 2016 study in the Journal of Archaeological Science: Reports. Hygiene sticks, also called bamboo slips, were wooden or bamboo sticks wrapped in cloth.

During the Greco-Roman period from 332 B.C. to 642 A.D., the Greeks and Romans cleaned their derrières with another stick called a tersorium, according to a feature in the BMJ. The tersorium, which had a sponge on one end, was left in public bathrooms for communal use. Some scholars argue that the tersorium may not have been used to clean people's behinds but the bathrooms they defecated in. People cleaned the tersorium by dumping it in a bucket of salt or vinegar water or by dipping it in running water that flowed beneath the toilet seats.

Greeks and Romans also tidied up with ceramic pieces rounded in the shape of an oval or circle, called pessoi. Archaeologists have found pessoi relics with traces of feces on them, and an ancient wine cup features a man wiping his bum with pessoi. Greeks may have also wiped with ostraka, ceramic pieces that they inscribed with the names of their enemies when voting to ostracize them. After the vote, they may have wiped their feces on their enemies’ names. However, these ceramic materials may have damaged the butt over time, causing skin irritation and external hemorrhoids, according to the BMJ.

In Japan in the eight century A.D., people used another type of wooden stick called a chuugi to clean both the outside and inside of the anus — literally putting a stick up their buttocks. And though sticks have been popular for cleaning the anus throughout history, ancient people wiped with many other materials, such as water, leaves, grass, stones, animal furs and seashells. In the Middle Ages, Morrison added, people also used moss, sedge, hay, straw and pieces of tapestry.

People used so many materials that a French novelist, François Rabelais, wrote a satirical poem on the topic in the 16th century. His poem gave the first mention of toilet paper in the Western world, but he called it ineffective. Rabelais instead concluded that a goose neck was the best option. Though Rabelais was joking, "feathers would work as well as anything organic," Morrison said.

Granted, even today toilet paper isn't universal. For instance, the Australian news outlet SBS Punjabi lightheartedly mocked Westerns desperate for toilet paper early in the pandemic, urging them to "wash not wipe" with a gentle jet stream of water. 

Originally published on Live Science.

If the Olympics awarded medals for long-distance pooping, penguins would take home the gold. 

These tubby, aquatic birds can squirt arcing jets of poop to distances nearly twice their own body length, and scientists recently calculated just how much force their tiny rectums produce in order to do so — and how far the poop can fly.

Over a decade ago, scientists had explored the pressure needed for chinstrap and Adelie penguins to expel poop along a mostly horizontal path, which they identified as penguins' most common poop direction. For a new study, which appeared on the preprint site arXiv on July 2 and has not been peer-reviewed, another team of researchers analyzed a different fecal trajectory in Humboldt penguins (Spheniscus humboldti), which often poop in a descending arc away from their nests on higher ground. 

Related: Photos of Flightless Birds: All 18 Penguin Species

The team of scientists who first addressed the penguin poo puzzle published their results in 2003, in the journal Polar Biology; that pioneering study won the authors an Ig Nobel Prize in 2005 for fluid dynamics. 

When a new team of researchers revisited the question, they expanded on the earlier results by recalculating internal pressures inside the penguin's gut and rectum, correcting for viscosity of the poo, and factoring in air resistance along an arcing trajectory. They then discovered that the forces at work were even more extreme than previously suggested. 

Pressure is measured in units called kilopascals (kPa), where 1 kPa is 1,000 newtons per square meter. In the new study, the scientists calculated that the pressure generated in the rectums of pooping penguins was as much as 28.2 kPa — about 1.4 times the estimate in the 2003 study.

"I was surprised by the extremely strong penguin's rectal pressure," said lead study author Hiroyuki Tajima, an assistant professor in the Department of Natural Science at Kochi University in Japan.

Though Humboldt penguins stand only 28 inches (71 centimeters) tall, the scientists discovered that the birds can generate enough poo-propelling energy to send fecal "bombs" flying at speeds of nearly 5 mph (8 km/h), landing up to 53 inches (134 cm) away. This achievement would be comparable to an adult human shooting their feces to a distance of more than 10 feet (3 meters), Tajima told Live Science in an email. 

Victor Benno Meyer-Rochow, lead author of the 2003 study, declared that he was "very pleased that other researchers have taken up our ideas to look into penguin pooping," according to Improbable Research, the humorous science organization that awarded Benno Meyer-Rochow the 2005 Ig Nobel Prize. 

The new study described the penguins expelling a fecal arc that curved upward before descending, which Benno Meyer-Rochow and his colleague had not seen in Adélie penguins. Nevertheless, "it is of course possible that either we missed that or that these penguins sometimes do that when they stand on an uneven rock and/or bend forward more than what we had observed," Benno Meyer-Rochow told Improbable Research.

Birds that eat meat or fish typically poop with more force than seed-eaters, likely because their waste contains higher amounts of irritating uric acid, Benno Meyer-Rochow wrote in a 2019 blog post.

While blasting poop jets helps penguins keep their nests tidy, their high-pressure pooping poses an occupational hazard for penguin caregivers in zoos and aquariums, the study authors reported. Their findings therefore have a practical side: helping wildlife experts who care for penguins to establish a foolproof "safety zone," so they can keep well out of range during the birds' explosive bathroom breaks, Tajima said.

Originally published on Live Science.

If you've ever wondered why men take so long to poop, you may have found yourself asking if there's a medical reason. Why else would some men take so much longer than women to take care of their business? 

The answer, however, does not appear to be anatomical. In fact, men might actually be quicker in discharging their defecatory duties than women are. One 2009 study in the journal Gender Medicine sought to investigate the gender differences of various pooping plights. The researchers looked at constipation, stool consistency, the need to use fingers to evacuate, and a host of other less-than-pleasant doody-related conditions. The team concluded that women were more likely to experience "abnormal bowel habits" and constipation than men. 

In other words, women tend to have more bowel-related troubles than men do. So, if anything, it's women who should be spending more time in the bathroom.

Related: Why is poop brown?

A 1992 study in the journal Gut found similar results. A questionnaire designed to assess gender differences in the bowel habits of nearly 1,900 men and women in England showed that while most people, regardless of their gender, don’t enjoy a "conventionally normal bowel function," statistically, it seemed women were more likely than men to face toilet-based challenges. 

But men really do spend more time in the loo. A recent U.K. survey conducted by the bathroom-appliance company UK Bathrooms, which the The Daily Mail covered, revealed that men spent an average of 1 hour and 35 minutes on the commode each week, or nearly 14 minutes a day, compared with women, who spend just 55 minutes a week on the toilet, or almost 8 minutes a day. 

That may mean that men who spend eons in the bathroom are doing more than just pooping. For example, research has found that 86% of men do most of their reading whilst sitting on the toilet, compared to just 27% of women, the UK Bathrooms poll found.

Another 2009 study, published in the journal Neurogastroenterology & Motility, found that of 499 surveyed men and women, more than half of men (64%) and less than half of women (41%) said they regularly read on the toilet.  

Perhaps these men do this because they are seeking solace from life's problems in the loo, Jonathan Alpert, a psychotherapist based in New York who wrote about how to overcome anxiety in the book "Be Fearless: Change Your Life in 28 Days" (Center Street, 2012), told Live Science. 

"Short of a medical explanation for someone spending a long time in the bathroom, there may be psychological reasons," he said. 

They may see toilet time as a way to get away from the bustle of a busy home, he said. “It may serve as their sanctuary and perhaps the only place they can actually have alone time."

It's especially true for fathers with young kids, who exploit the excuse of a prolonged poop for a chance to recollect their thoughts, he said. "I've had some clients tell me that the bathroom allows for the perfect escape from parenting duties," Alpert noted. "It can be a hideout for people because no one ever asks what you're doing in there, even if you take a long time. It can truly be a safe place."

(Let's take a moment to note that fathers spend less time on childcare and household duties than mothers do, according to data from the Bureau of Labor Statistics. These surveys also find that dads have more leisure time than moms do — perhaps they are squandering their leisure time in the toilet?)

Alpert added that "everyone deserves their privacy to go to the bathroom, and I think some people might be using it for a little more than that and to their advantage." However, sitting on the toilet for an extended period of time can have drawbacks. Doctors caution that sitting (and pushing) for too long on the toilet can cause a build up of pressure in the anus that eventually leads to hemorrhoids. 

Lengthy lavatorial sessions, moreover, can also be a harbinger of more sinister behavior. "For some people, there may be reasons for concern that might be far more serious — especially if a phone accompanies them to the bathroom," Alpert said. "Many people have corresponded with their side girlfriend or boyfriend while sitting on the can. Still others have watched porn or swiped left or right on their dating apps."

But don't rush to conclusions if the man in your life is spending an unfathomable chunk of time on the toilet; in all likelihood he probably just wants a few extra minutes of alone time. 

Originally published on Live Science.

A greasy, sandy diet left a northern curly-tailed lizard with a belly distended by a heavy ball of unpassable poop. The mass was so large that it made up nearly 80% of the animal's body weight — a record-breaking body-to-poop ratio, according to a Florida biologist.

As the lizard gulped down insects and other small reptiles near a pizza parlor in Cocoa Beach, Florida, it also swallowed particles of grease-soaked sand. Over time, the grains stuck together to form a lump that was too dense for the lizard to excrete, said Natalie Claunch, the researcher who found the lizard, and a doctoral candidate in the School of Natural Resources and Environment at the University of Florida  in Gainesville.

And the more that the constipated lizard ate, the bigger the poop mass grew. 

Naturally, when Live Science's editor-in-chief heard about this, she responded: "Dump everything and write." 

Related: Images: Exotic lizards pop out of the ground in Florida

If only the unfortunate lizard had had that option. But by the time Claunch found the reptile, it was unable to excrete the tightly-packed, sandy mass. All nutrients had been sucked out of the dense ball in its gut, and the lizard was nearly out of room to eat anything more; it was slowly starving to death and was therefore humanely euthanized, Claunch wrote in the March 2020 issue of the journal Herpetological Review.

When Claunch picked up the pear-shaped lizard — a female — she recognized right away that the mass stretching its belly wasn't a cluster of ready-to-lay eggs. 

"Eggs feel like large jelly beans, and you can feel them individually," she told Live Science in an email. "This was a semisolid putty-like mass."

Dissection showed that the lizard's internal organs were so squeezed that they had atrophied, particularly its ovaries and liver. The mass was so dense that it was even visible in computed X-ray tomography (CT) scans, said Edward Stanley, an associate scientist in the Florida Museum of Natural History's Department of Herpetology.

When Stanley performed the scans, he was "a bit nervous" about handling the delicate, bloated body "because it was so full," he told Live Science.

"I was concerned that unless I was careful, I might pop it," he said.

The lizard weighed about 1 ounce (28 grams), and the mass alone weighed 0.8 ounces (22 grams), or about 78.5% of the lizard’s total weight. This represents "the largest feces-to-body mass ratio recorded in a living animal," Claunch reported. To put that into perspective, scientists previously documented a Burmese python (Python bivittatus), a species known for digesting enormous meals (and excreting huge poops), that produced a fecal mass representing a mere 13% of the snake's body weight, Claunch wrote.

Inside the bolus were the remains of an earlier meal — the skull of an anole, which are part of the lizard’s natural diet, said Stanley.

Northern curly-tailed lizards (Leiocephalus carinatus) are native to the Bahamas and other Caribbean islands; they were introduced in southeastern Florida in the 1940s, when a Palm Beach resident released several dozen of the lizards on his property to combat insect pests, said Hank Smith, a professor at Florida Atlantic University and a wildlife biologist for the Florida Park Service. 

In the decades since their release, the voracious invading lizards have replaced many of the smaller native lizard species — some of which have become the curly-tailed lizards' prey.

"They're the T. rex of our little ground critters," Smith told the South Florida Sun-Sentinel in 2006.

This isn't the first curly-tailed lizard with pervasive poop problems; Claunch and her colleagues have found three other individuals with fecal masses that were 30% or more of their body weight. 

"We had actually found a curly-tailed lizard similar to this one the year prior, near the same location, with a fecal mass nearly 40% of its total body mass," Claunch said.  However, it's unclear how long it may take these sand-packed masses to accumulate in a lizard's gut.

"There is no good way to tell because we don’t have studies on 'normal' digestion in the species to compare to, yet," Claunch said.

• Photos: Gorgeous Shots of the Adorable Horned Lizard
• Album: Bizarre Frogs, Lizards and Salamanders
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Originally published on Live Science.

In this episode of Life's Little Mysteries, we'll take a closer look at a mysterious bodily function that is as fascinating as it is gross — poop. Just about every living thing poops; poop is an important indicator of everyday gut health, and poop plays an important role in ecosystems and animal diets, providing essential nutrients that benefit organisms of all sizes. 

Have you ever wondered why coffee makes you poop, why some animals eat their own poop, and how much you poop in your lifetime? Listen to Life's Little Mysteries 11: Mysterious Poop, to find out!

We'll also hear from a researcher who tested the cutting edge of a knife made from frozen poo, and a Live Science reporter will explain how scientists learned that the novel coronavirus can be transmitted through feces.

Co-hosts: Jeanna Bryner and Mindy Weisberger

Guests: Metin Eren, assistant professor at Kent State University in Ohio, and co-director of the Eren Laboratory of Experimental Archaeology; Yasemin Saplakoglu, staff writer at Live Science.

Listen to Life's Little Mysteries 11: Mysterious Poop below or on Audioboom, or subscribe on Apple Podcasts and Spotify, so you don’t miss out on new episodes.

Follow us on Facebook and Twitter for even more Life's Little Mysteries, and catch up on the latest Life's Little Mysteries articles. You can also join the conversation in our forums, where you can pose Life's Little Mysteries questions of your own, or even suggest topics for upcoming podcast episodes. 

Originally published on Live Science.

Humans produce a lot of poo. An average adult flushes about 320 lbs. (145 kilograms) of it down the toilet each year. But what happens to all that waste?

It turns out that the stuff we flush down the toilet is surprisingly useful. A significant portion of flushed poo, in fact, ends up fertilizing crops that we eventually eat, said Daniel Noguera, a civil engineer at the University of Wisconsin-Madison. Some of our poop gets used as fuel, heating the very facilities that process our waste. And the rest eventually reaches landfills. But before the fate of your poop is sealed, a long series of steps ensures it's free from disease, and safe for farms and waterways.

From the toilet, your poop flows through the city's sewage system along with all the water that drains from our sinks, showers and streets. From there, it goes to a wastewater treatment plant. 

Related: Why Is Poop Brown?

There are three stages of wastewater treatment, according to the New York City Department of Environmental Protection. During the first stage, all of the waste that accumulates in the city's pipes just sits in a tank for hours. This stage allows the solids to settle at the bottom of the tank. The water at the top of the tank is skimmed off and sent off to be processed. Your poop remains in the sludge that's left over. (The official name for this goop is, in fact, sludge.)

The second step, called the activated sludge process, uses biology to make sure our poop is squeaky clean. Billions of microorganisms that are already in the poop breathe in oxygen and munch on pollutants such as nitrogen and phosphorous, cleaning the sludge in the process. These pollutants could otherwise cause massive algae overgrowth in waterways or react to form toxic compounds, like ammonia. 

In the next tank, called a digester, low oxygen and hot temperatures (around 95 degrees Fahrenheit, or 35 degrees Celsius) create the perfect conditions for anaerobic bacteria, which thrive without oxygen. The anaerobes further break down the waste inside the tank, converting most of it into water, methane and carbon dioxide. (Some treatment plants even reuse this gas as fuel.) Unlike anaerobes, most pathogens don't fare well in these inhospitable conditions, and most die off at this stage, Noguera said. 

The activated sludge process is incredibly effective but nothing high tech. "We've been using these technologies for a very long time," Noguera told Live Science — 103 years, to be precise. In wetlands, rivers and streams, these same bacteria and biochemical processes have been purifying water for much longer. "We just replicate what nature does," Noguera said. 

At this final stage, the sludge is mostly liquid, so the next step is to dry it out as much as possible. A contraption called a centrifuge operates like a dryer on its spin cycle, whirling that sludge around until centrifugal force removes most of the water. The dried-out sludge leftovers are called biosolids — and they're incredibly useful.

An adult’s poop eventually yields 47 lbs. (21 kg) of biosolids each year, according to a 2002 report from the National Academies' National Research Council. So, what happens to the biosolids? Around 55% gets used for agriculture. (However, the chance that the lettuce and tomato in your BLT were grown using human poop is negligible — only about 1% of all the farmland in the U.S. uses biosolids as fertilizer. That's because farmers use more fertilizer than poop can provide, meaning that farmers tend to use other types of fertilizer.) Around 17% of biosolids are incinerated — some, but not all of that, gets used to produce energy. The rest winds up in landfills. 

There's a growing push to put more biosolids to use, Darren Olson, a civil engineer at Christopher B. Burke Engineering in Chicago, told Live Science. New York City, for example, is aiming to stop sending biosolids to landfills by 2030, according to the New York City Department of Environmental Protection. There's even a push to increase our use of biosolids as fuel. (Imagine a poop-powered home!) 

For now, you can still pat yourself on the back when you flush the toilet. There's a pretty good chance you're helping a farmer. 

• Why Is My Poop Green?
• Why Do You Get Diarrhea When You're Sick? 
• Why Do Some of Us Shiver When We Pee?

Originally published on Live Science.

Scientists ponder a wide variety of probing questions in pursuit of knowledge. One of those questions — can a knife made of frozen feces cut flesh? — has just been answered.

An anthropologist reported in the 1990s that there was "a well-known account" of a stranded Inuit man crafting a knife from his own, frozen excrement that was sharp enough to kill and butcher a dog. The tale quickly spread through academic circles, its fame growing over the decades. But no evidence suggested that the incident ever took place or that such a blade would even be possible to shape or use.

That is, until now. A team of researchers in a laboratory that reverse-engineers ancient tools was intrigued by the story and decided to put it to the test. In the name of science, the lab's co-directors generated the experiments' raw materials and then crafted their own frozen poop knives, describing the process — and the disappointing outcome — in a new study. 

Related: 11 Surprising Uses for Pee and Poop

In 1998, anthropologist and ethnobotanist Wade Davis published the book "Shadows in the Sun: Travels to Landscapes of Spirit and Desire." It included the remarkable account of an elderly Inuit man left alone during a freezing storm with no tools; he allegedly survived the ordeal by carving a knife from his frozen feces, "sharpened with a spray of saliva," Davis wrote. 

Then, the man killed a dog with the knife, butchered the beast and "disappeared into the darkness" riding a sled that he made from the animal's rib cage.

Davis later said that he suspected the Inuit man who told him the story may have been toying with him. True or not, the story has since grown to become "one of the most popular ethnographic accounts of all time," according to the study. 

Real knife, or fake news?

When lead study author Metin Eren was still in high school, he heard Davis telling the story of the knife-wielding Inuit man on the radio; Erin told Live Science that the experience fueled his decision to become an anthropologist — he's currently an assistant professor at Kent State University in Ohio, and co-director of the university's Eren Laboratory of Experimental Archaeology.

It was in that lab where the next chapter of the poop-knife story unfolded. The dubious case of the frozen poop knife presented Eren with an intriguing subject for the lab's hands-on approach to unraveling how ancient tools work. 

Given the current political climate, in which so-called alternative facts are alarmingly common and accusations of "fake news" are freely flung, "I thought it would be really important to do a project that tests some sort of urban legend, or something that is pervasive in the academic and public sphere that hasn't been well-tested and supported by experimental data," Eren said.

Related: In Photos — Human Skeleton Sheds Light on First Americans

Before conducting any experiments, Eren; co-author Michelle Bebber, also an anthropologist at Kent State; and their lab colleagues needed raw material for shaping the knives. Eren therefore adopted an eight-day "arctic diet" that was high in protein and fatty acids. His menu included lots of beef, turkey and salmon, with isolated helpings of applesauce, mac and cheese, and butternut squash risotto, according to the study. 

By the fourth day, he was producing samples that were suitably "arctic" and usable in the experiments. The researchers froze the specimens to temperatures of minus 58 degrees Fahrenheit (minus 50 degrees Celsius), sharpening the poop blades with metal files and keeping them chilled with dry ice until they were ready to be tested on refrigerated pig hide.

"I was surprised at how hard human feces could get when frozen," Eren said. "I started to think, 'Oh my gosh, this might actually work!'"

But in the end, the poop knives simply didn't make the cut.

"Like a crayon, it just left brown streaks on the meat — no slices at all," he said. 

Bebber then provided additional sample material of her own, but knives from the new poo fared no better.

"This idea that a person made a knife out of their own frozen feces — experimentally, it is not supported," Eren said.

Though the experiments demonstrated that a blade made of frozen waste couldn't carve flesh — or even penetrate it — the researchers' efforts were far from wasted, Eren said.

"Data is key, and really, that's where this study is meant to draw the reader. Science is about describing and explaining reality. Especially in this day of alternative facts and fake news, evidence needs to come back to the fore."

The findings were published online in the October issue of the open access Journal of Archaeological Science: Reports.

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• How Much Do You Poop in Your Lifetime?

Originally published on Live Science.

Going to the zoo can be a great adventure, especially if you find poop hurtling in your direction. The likely perpetrators, chimpanzees, are known to sometimes throw their feces at visitors. But what's the reason behind this behavior?

And, more importantly, should you consider yourself lucky to be the center of their attention?

Throwing feces is not a regular occurrence for primates, at least not most of them. Primates in the wild don't normally throw feces, Karen Strier, a professor of anthropology at the University of Wisconsin-Madison, told Live Science. It's typically observed in captive populations of chimpanzees, although other primates, such as wild howler monkeys in western Belize, are also known to throw poop. [Why Haven't All Primates Evolved into Humans?] 

In her research, Strier studies the northern muriqui (Brachyteles hypoxanthus), which may be one of the most peaceful primates in the world. These animals live in the forests of Brazil, and they don't have social hierarchies in their groups. This even-footing might make aggression unnecessary, at least for those monkeys, Strier said.

Chimpanzees (Pan troglodytes), on the other hand, do have hierarchical social groups. They are known to drag tree branches or throw rocks when they are frustrated or annoyed or when they want to display dominance.

"They're capable of expressing so much … they're really good communicators," said Ronnie Steinitz, a doctoral student in the Integrative Anthropological Sciences program at the University of California, Santa Barbara. Throwing rocks and branches is part of how these animals communicate, and being a good communicator can be an advantage in their society. For example, a male chimpanzee who can get back on the good side of an alpha male after a fight — meaning he's likely a good communicator — might not get shunned from the group. Experts think that in male chimpanzees reconciling after an aggressive conflict leads to social bonding and helps to establish the hierarchy.

Moreover, a 2012 study published in the journal Philosophical Transactions of the Royal Society B suggested that chimpanzees that are better at throwing objects have more developed brains.

In zoo environments, especially if groups of people are staring at them, the chimps may get riled up or frustrated, and they may decide to convey that emotion to their captive audience.

"Since they're usually deprived of rocks, or branches, or any small objects like that, for this exact reason, they opt for the next best thing that they have within reach, which is usually poop," Steinitz told Live Science. This explains why you might need to take cover next time you're at the ape house.

However, there is a silver lining: If you're not bothering the chimpanzees, you should be flattered that these primates consider you worthy of their poop-throwing attention.

"Think of it as another intelligent being trying to communicate with you," Steinitz said.

Editor's Note: This story was updated to clarify that chimpanzees aren't the only known primates that throw poop.

• Why Is Poop Brown?
• Why Do Some Animals Eat Their Own Poop?
• Why Do Cats Bury Their Poop?

Originally published on Live Science.

Waste? Not!

When most animal bodies process nutrients, they expel waste in the form of liquids and solids — generally referred to as urine and feces. Waste is usually smelly and unappetizing (for people, at least) but it can also be surprisingly beneficial. Pee and poo have a wide range of applications; providing nutrients for diverse ecosystems, serving as a foundation for expensive perfumes, or even fueling robots. 

Here are just a few of their unexpected uses.

From poop to perfume

A yellowish-grey "rock" found on a beach in the UK was greasy and smelled terrible — and no wonder, as it originated in the guts of a sperm whale. The slick, malodorous lump was a sizable chunk of ambergris, a fatty substance thought to form in whales' digestive tracts around sharp objects such as squids' beaks. 

Whales then poop out the ambergris, which is highly prized by humans as an ingredient in pricey fragrances. The lump found on the beach was estimated to be worth at least $68,000, and possibly as much as $180,000.

To dye for

A 1,500-year-old Byzantine copy of the New Testament known as the Codex Purpureus Rossanensis is printed on purple pages, and researchers recently uncovered the long-held secret behind the parchment's vivid color — urine. 

Analysis of the tome revealed that the pages derived their purple hue from orcein — a dye extracted from the fungus Roccella tinctoria, and then processed with fermented urine. The manuscript, which is about half-complete, is written in gold and silver ink on 188 pages, and likely originated in Syria between the 5th and 6th centuries A.D.

Tastes like...

Researchers in Japan recently brought a stomach-turning offering to the table, by transforming human feces into steak. At the request of Tokyo Sewage, scientists investigated practical uses for excess sewage, and discovered that they could isolate proteins from the bacteria in human waste; combined with carbohydrates and fats, the result could be served as a meatlike substance.

Experts told Live Science that while it should be possible to make something edible — and safe to eat — using this method, cooking the "steak" before consuming it is still strongly recommended.

Drink up

Don't want to eat steak made from poop? How about drinking a nice glass of water...that used to be poop? An innovative processing system called the Omniprocessor heats sewage sludge, separating the liquid as water vapor that is then treated to make it suitable for drinking.

With human populations on the rise in many countries, access to clean water and sanitation is a growing challenge worldwide. Processing systems such as this could provide an efficient solution to both problems, according to Bill Gates, whose foundation is funding development of the technology.

Building blocks

Bricks made from urine could one day serve as cheap, sustainable building materials for homes and other structures. But how do you turn pee into a brick? Scientists mixed with fresh urine with lime — calcium hydroxide powder — strained the liquid, and then combined it with sand and bacteria, which turn the material into a cementlike substance.

The bricks are sturdy; about as hard as limestone. They set at room temperature, so their production don't require a coal- or wood-burning oven. As the bricks are setting they do exude an unpleasant urine aroma, though the smell subsides in about 48 hours.

Poop-eroni

Poop sausagemay not sound like a tasty treat, but scientists have figured out how to use bacteria from baby poop to make sausages that are both delicious and healthy. Microbes are already harnessed to produce delicacies like cheese, wine and beer — and fermented sausages. And baby poop is chock-full of microbes; particularly Lactobacillus and Bifidobacterium, which are used in probiotics.

Using bacteria cultured from poop in babies' diapers, researchers made a type of Spanish fermented pork sausage called "fuet," and they claimed that it tasted "very good."

Urine therapy

In India, cow urine has been used for therapeutic purposes for at least 5,000 years, and a Hindu group that promotes drinking cow urine for its health benefits recently claimed that the liquid "offers a cure for around 70 to 80 incurable diseases like diabetes," according to Om Prakash, of the Cow Protection Department for the Hindu sect Rashtriya Swayamsevak Sangh (RSS). 

However, health experts have questioned the effectiveness of remedies containing cow urine, particularly when it is purported to treat or prevent cancer.

Robot fuel

The pumping action of an artificial heart sends urine coursing over a microbial fuel cell, in a device that could power pollution-monitoring robots. Dubbed EcoBots, these pee-powered bots represent technology that recycles waste into electricity. 

Their fuel cells harness living microbes such as those that colonize the human gut — and sewage treatment plants. When the microorganisms digest urine they produce electrons, which can then be harvested to generate an electrical current. And urine isn't the nastiest fuel source these robots have used — previous versions ran on energy extracted from sludge,wastewater, dead flies, and rotting produce.

Worm 'towers'

Giant soil mounds in the grasslands of Colombia and Venezuela alternate with deep pits in the ground, and the mounds were formerly thought to be the result of erosion or termite activity. But scientists recently discovered that they were made of piles and piles of worm poop, collecting in locations that the worms would visit for generations.

Worms measuring up to 3 feet (1 meter) in length eat and digest dirt, excreting pellets known as casts. Over time, the mounds can grow wider than 16 feet (5 meters) in diameter, and groups of them form an impressive landscape features called a surale, which is also found in Uganda, New Guinea and South Africa.

Poop-biotics

Could a path toward better health begin with a baby's diaper? Baby poop — specifically, the microbes inhabiting babies' guts — could one day produce potent probiotics to address digestion disorders.

What's so special about baby poo-microbes? Some types of microorganisms in baby poop promote the production of molecules called short-chain fatty acids, which are associated with a healthy gut. Fecal transplants with these microbes could help to correct imbalances in the gut, promoting the growth of beneficial bacteria and protecting against disease. 

Ocean fertilizer

Whales are among the largest living creatures on Earth — as such, they generate enormous quantities of pee and poop. And that's a good thing, as their waste provides critical nutrients for a variety of marine creatures.

Whales typically relieve themselves at the sea surface before they dive, leaving behind a "fluffy" effluvia plume. This fecal feast releases nutrients that originated in ocean depths and nourish phytoplankton — tiny marine plants — which live close to the surface, and play an important part in ocean food webs.

A 210-foot-long (64 meters) monster made from grease and used baby-wipes has clogged up a sewer in Sidmouth in southwestern England. British officials said in a statement they expect that removing the gooey blob, which will happen in "exceptionally challenging work conditions," could take up to eight weeks.

"Fatbergs" like this one have become unpleasantly familiar in the United Kingdom. As Live Science reported back in 2017, workers used high-pressure water jets to slowly break down an 820-foot-long (250 m), 143-ton (130,000 kilograms) "rancid blob" that formed in a London sewer. Eventually, that mass was converted to biofuel, but it took workers months to fully restore function in the affected area. [The Poop on Pooping: 5 Misconceptions Explained]

(Another chunk of that fatberg, according to the Associated Press, ended up on display at the Museum of London.)

Part of the problem seems to be the British public's habit of flushing used baby wipes down the toilet, as these can clump together and form the scaffolding for fatbergs. The issue has become serious enough that the government has proposed banning the wipes altogether.

For now officials in Sidmouth are asking residents to avoid contributing to this new mass before workers can remove it, saying, "Don't feed the fatberg."

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Originally published on Live Science.

WASHINGTON, D.C. — Traces of 1,000-year-old poop in Peruvian soil could reveal the history of alpaca domestication in the region.

Researchers analyzed sediments from cores extracted from lakes in southeastern Peru. They were looking for chemical "fingerprints" of compounds called sterols, which appear when cholesterol is broken down during digestion, and are expelled in feces, the scientists reported today (Dec. 10) in a presentation at the annual meeting of the American Geophysical Union (AGU). [5 Things Your Poop Says About Your Health]

One type of sterol, 5b-stigmastanol, is associated with the guts of ruminants — animals that chew their regurgitated cud — such as alpacas. Another type, called coprostanol, is produced in the human gut.

By evaluating the ratio of alpaca poop-chemical to human poop-chemical, researchers were able to estimate when human populations may have begun domesticating and living alongside alpacas.

In samples from Lake Arapa in Peru, alpaca sterols became more prevalent after the beginning of the Wari Empire (about A.D. 600) and were well-established by the time of the Inca Empire, around A.D. 1400, research co-author Thomas Elliott Arnold, an organic geochemist and postdoctoral scholar with the Department of Geology and Environmental Science at the University of Pittsburgh, told Live Science.

A similar ratio emerged in samples from Lake Orurillo, Arnold added.

Since 5b-stigmastanol is found in other ruminants, such as deer — which are also native to that part of Peru — is it possible that the sterols in the samples could represent deer instead of alpaca? Not really, Arnold said, because there isn't a good explanation for what might have caused a sudden and dramatic increase in deer populations in A.D. 1,000, when the researchers found a sterol spike.

"You'd have to assume a bunch of deer suddenly went on a mating frenzy and congregated in and around the Orurillo region," Arnold said.

A more reasonable explanation is alpaca domestication, Arnold said.

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Originally published on Live Science.

Earlier this year, six pediatric scientists decapitated six Lego minifigures, then swallowed the heads. The researchers did this to answer a simple, scientific question: How long does it take to poop a brick?

The answer, for those of you teetering on the edges of your seats, is about two to three days. The researchers know this because they picked apart every poo they made after swallowing the heads, until the unfortunate yellow faces were successfully retrieved. You can read all about it in the team's new study in the Nov. 22 issue of the Journal of Paediatrics and Child Health, playfully titled, "Everything Is Awesome: Don't Forget the Lego."

"This study was a bit of fun in the run-up to Xmas," Dr. Tessa Davis, a consultant in pediatric emergency medicine at Royal London Hospital and one of the bold study authors/Lego-swallowers, told Live Science in an email. "But actually, we get children presenting to the emergency department every day with ingested foreign objects." [11 Weird Things People Have Swallowed]

According to a 2006 report in the journal Current Opinion in Pediatrics, about 100,000 people in the U.S. ingest a nonedible object every year; about 80 percent of those cases occur in children ages 6 months to 3 years. Some swallowed objects, such as button batteries or someone else's medication, can pose significant health risks that require swift medical intervention. However, the most commonly swallowed objects — coins and tiny toy parts — often pass through the swallower's system without causing a disturbance.

Still, Davis said there's hardly any scientific literature looking at the precise effects of swallowed toys in children or adults. To fill that research gap in the simplest (and arguably funniest) way possible, Davis and five colleagues in Australia and the U.K. took it upon themselves to swallow — and then painstakingly retrieve — the world's most popular toy.

In a coordinated event, each researcher swallowed a single, smiling Lego head early one morning this year. For the three days before that, each participant had kept a detailed "stool diary" to monitor the hardness and frequency of their bowel movements. To do so, they used a custom rating system they called the Stool Hardness and Transit scale — aka, SHAT.

After swallowing their Lego heads, each researcher monitored and SHAT-rated their every bowel movement until each head was successfully retrieved on the other side (with one exception). The methods of retrieval were open to the participant's preferences. Plastic bags were a common tool of choice. Some of the doctors employed tongue depressors; others used chopsticks. Davis' retrieval involved "gloves, a cat fork and a vomit bowl. I'll leave the rest to your imagination," she said.

Luckily, it took Davis only two bowel movements to recapture her Lego head. This gave her a Find and Retrieval Time (aka, FART) score of 1.42 days. Two participants found their heads after a single bowel movement (which occurred between 27 and 32 hours after the initial swallowing), while two others found theirs after three stools. One unfortunate participant never found his Lego head. According to Davis, "he had to search every stool for two weeks." [5 Things Your Poo Says About Your Health]

What does this research tell us? For starters, it suggests that swallowing a Lego head isn't super dangerous, at least for a healthy adult. When the participants compared their SHAT scores from before the head-swallowing event to their own scores from afterward, they found that the consistency and frequency of their poos had not significantly changed. (The authors noted that the uniform roundness of Lego heads might help ease their passage through the body; repeating the study with sharp objects, like Lego legs or torsos, would carry a higher likelihood of internal damage or blockage.)

Secondly, we've learned that attempting to find objects in yours or someone else's stool is difficult and gross and probably shouldn't be done at home. "If an experienced clinician with a Ph.D. is unable to adequately find objects in their own stool, it seems clear that we should not be expecting parents to do so," Davis and her colleagues wrote in the study. "The authors feel that national guidance could include this advice."

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Originally published on Live Science.

How talented is your anus? Probably not as talented as a wombat's. That cuddly Australian marsupial's rear end has a mysterious and magical ability: It makes cubic poops. And now scientists think they know how.

Cubed wombat poop is one of those wonders of the animal kingdom, like the giant body of the blue whale or the superfast punch of the mantis shrimp, that seems like it shouldn't work on a basic physical level. There's a reason poops are usually spheres or tapered cylinders: Try squeezing a cube out of a tube of toothpaste. Round chutes and round holes like to produce round things.

But in new research presented at the 71st Annual Meeting of the APS Division of Fluid Dynamics on Nov. 18,a team of researchers led by Patricia Yang of the Georgia Institute of Technology said that they've figured it out. [Facts About Wombats]

Feces travel through most of the wombat intestine as liquid slurry, but they dry up into a solid for the last 8 percent of the journey. And that's when the cubic magic happens.

"By emptying the intestine and inflating it with a long balloon, we found that the local strain varies from 20 percent at the cube's corners to 75 percent at its edges," the researchers wrote.

In other words, the intestine is more elastic in some places than others, so it pushes down on its contents harder in some places than in others, creating the little blocks. According to Yang, it's a whole new, previously unknown method for making cubes.

"We currently have only two methods to manufacture cubes: We mold it, or we cut it. Now, we have this third method," she said in a statement. "It would be a cool method to apply to the manufacturing process — how to make a cube with soft tissue instead of just molding it."

Wombats go through all this effort for a reason, the statement said. They don't see or hear very well, so they stack their poops in important places to guide themselves around and to signal their presence to other wombats. A big pile of cubic poops is the wombat equivalent of a "Hello, there."

They just had to invent an all-new method of cube production to pull it off.

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Originally published on Live Science.

Tiny particles of plastic are seemingly everywhere: So-called microplastics have been found in the ocean, tap water, bottled water and soil. Now, they've even been found in our poop.

In a small, first-of-its-kind study, researchers have found microplastics in stool samples from people around the world.

The study "confirms what we have long suspected, that plastics ultimately reach the human gut," study lead author Dr. Philipp Schwabl, a physician scientist at the Medical University of Vienna's Division of Gastroenterology and Hepatology, said in a statement.

Little is known about the health effects of microplastics, but there's concern that the pervasive plastics may affect our gastrointestinal (GI) health and possibly reach other organs. "Now that we have first evidence for microplastics inside humans, we need further research to understand what this means for human health," Schwabl said. [9 Disgusting Things That the FDA Allows in Your Food]

Schwabl presented his findings today (Oct. 22) at UEG Week in Vienna, a European gastroenterology meeting. The findings have not yet been published in a peer-reviewed journal.

Microplastic pollution

Microplastics are bits of plastic that measure under 0.2 inches (5 millimeters) in length — about the size of a sesame seed or smaller. They're formed when larger pieces of plastic pollution break down. Microplastics can wind up in the oceans or the Great Lakes, where the particles are ingested by aquatic life and enter the food chain. Indeed, microplastics have been detected in seafood, including tuna, lobster and shrimp, the researchers said. Humans are also likely exposed to microplastics as a result of plastic contamination from food packaging or processing.

Still, data on human exposure to microplastics is scarce, and the new study is the first to quantify the particles in human stool, the researchers said.

In the study, the researchers analyzed stool samples from eight healthy volunteers living in eight countries around the world: Finland, Italy, Japan, the Netherlands, Poland, Russia, the United Kingdom and Austria.

Using a new type of analytical procedure, the researchers found microplastics in all of the stool samples they received. The most common types of plastic found were polypropylene and polyethylene terephthalate — two plastics that have a wide range of uses, including plastic bottles. On average, the researchers detected 20 microplastic particles per 10 grams of stool.

The participants were not told to eat any specific diet, but food diaries showed that six of the participants consumed fish in the week before giving a stool sample, and all of the participants consumed at least some plastic-wrapped foods or drank from plastic bottles.

Although the study was small, the fact that microplastics were found in all of the samples "indicates a high likelihood that also many other people involuntarily ingest microplastics," Schwabl told Live Science.

The researchers are planning to conduct a larger study to confirm the findings, and to see if they can identify factors linked with microplastics in stool, such as a person's diet, lifestyle or where they live, Schwabl said.

The researchers are also planning further studies to investigate the effects of microplastics on human health. Animal studies suggest that microplastics can enter the bloodstream and lymphatic system, and may reach the liver, Schwabl said. In addition, microplastics may cause damage to the intestines and affect how well the body absorbs nutrients, he said.

Originally published on Live Science.

Could the key to better gut health reside in a probiotic cocktail brewed from the contents of an infant's dirty diaper?

That's the question driving a new line of research investigating the power of baby poop as a potential source of microbes that could contribute to healthier digestion. And experiments recently showed that certain types of bacteria extracted from baby feces could promote the production of short-chain fatty acids (SCFA) in mice, and in a medium simulating the human gut.

SCFA molecules are a subset of fatty acids that are churned out by some types of gut microbes during the fermentation of fiber. They're associated with maintaining gut health and protecting against disease, so a probiotic containing baby-poop microbes could provide health benefits by boosting SCFA production in a compromised digestive system, researchers reported in the new study. [5 Ways Gut Bacteria Affect Your Health]

"Short-chain fatty acids are a key component of good gut health," lead study author Hariom Yadav, an assistant professor of molecular medicine at Wake Forest School of Medicine, said in a statement. "People with diabetes, obesity, autoimmune disorders and cancers frequently have fewer short-chain fatty acids. Increasing them may be helpful in maintaining or even restoring a normal gut environment, and hopefully, improving health," Yadav said.

Fecal microbiota transplants (FMT), or "poop transplants," can treat a type of gut disorder with an infusion of diverse bacteria from a healthy digestive system, distilled from a donor's poop. This helps to correct imbalances of microbial diversity when the gut microbiome is dominated by the bacteria Clostridium difficile (C. diff), which can lead to serious gut disorders. 

Previous studies have investigated the use of probiotics — those healthy gut bacteria — by testing their impact in guts already affected by disease, the researchers wrote in the study. For the new investigation, they wanted to see how a probiotic would impact SCFA production in a healthy gut. They chose to work with baby poop because infants' gut microbiomes are typically free from age-related diseases "such as diabetes and cancer," and because of the sheer abundance of infant feces at their disposal. ("Their poop is readily available," Yadav said.)

In the small, new study, the researchers isolated 10 bacterial strains — five species of Lactobacillus bacteria, and five species of Enterococcus — in samples from 34 babies, identifying the strains as good candidates for crafting a probiotic cocktail of microbes that could survive in a human host's gut and stimulate SCFA production, according to the study.

They then tested different doses of the 10-bacterial probiotic blend in mice, as well as in a slurry of human feces meant to mimic the environment of a human digestive system. The scientists found that even single doses maintained the healthy microbial balance and increased SCFA production in both the mice and the feces medium, the researchers reported.

"This work provides evidence that these human-origin probiotics could be exploited as [treatments] for human diseases associated with gut microbiome imbalance and decreased SCFA production in the gut," Yadav said.

Still, much more research is needed before you'll find baby-poop probiotics on the shelves of your health-food stores.

"Our data should be useful for future studies aimed at investigating the influence of probiotics on human microbiome, metabolism and associated diseases," Yadav said.

The findings were published online Aug. 23 in the journal Scientific Reports.

Some of us carry a security blanket to feel more comfortable when we are far away from home. North Korean leader Kim Jong Un reportedly carries a security toilet.

According to the South Korean newspaper Chosun Ilbo, Kim arrived in Singapore this morning (June 11) for a nuclear disarmament summit with U.S. President Donald Trump, and he brought his personal toilet with him. [North Korea: A Hermit Country From Above (Photos)]

Indeed, it is said that Kim never leaves home without a personal lavatory, and actually travels with several toilets every time he's on the road, the South Korean news site Daily NK previously reported. The leader's amenities include an emergency "chamber pot" in his Mercedes, that report said, as well as a designated toilet car in his motorcade. A separate mobile commode designed to handle "mountainous terrain and snow" may also join the leader's caravan as needed, according to an unnamed source privy to the leader's privy, Daily NK reported.

While anyone who has ever taken a road trip can understand the appeal of entirely avoiding public restrooms, Kim's mobile throne is also said to serve a national security purpose. Lee Yun-keol, a former member of a North Korean Guard Command unit, told The Washington Post that "the leader's excretions contain information about his health status so they can't be left behind." As Chosun Ilbo put it, the mobile lavatories "deny determined sewer divers insights into the supreme leader's stools."

How many secrets could Kim's stools actually hold? It turns out, a lot. [5 Things Your Poop Says About Your Health]

"The digestive tract contains more bacterial cells than there are cells in the entire body," Dr. Jean-Pierre Raufman, a gastroenterologist at the University of Maryland School of Medicine, previously told Live Science.

Not only is this dense bacterial biome like a fingerprint that contains the pooper's unique DNA, but it can also reveal whether that person's bowels are absorbing the nutrients they need and rejecting the germs they don't.

According to Raufman, the shade of Kim's stool could indicate, for example, whether the leader is bleeding internally or taking medication to treat an iron deficiency. Overly narrow stools could indicate a blockage in Kim's colon, which could be a sign of intestinal cancer. A poor diet or reliance on certain medications could result in constipation — which, if untreated, could lead to hemorrhoids or rectal bleeding. Persistent diarrhea, on the other hand, could be a sign of chronic disease such as irritable bowel syndrome or Crohn's disease.

Kim, who often relies on images of strength and power to bolster his leadership, would likely sooner keep his health status — and his poos — to himself (and his medical team). On this, at least, we can't say we blame him.

Originally published on Live Science.

Domestic dogs are known to enjoy chewing large bones, but they lack the jaw strength to pulverize them. In fact, in today's ecosystems, the only large predators with skulls and jaws powerful enough to splinter bones are hyenas. But that wasn't the case millions of years ago, researchers reported in a new study.

Scientists had known from years of analyzing fossils of a wolf-size species of wild dog called Borophagus parvus — which lived from about 16 million to 2 million years ago — that its skull and powerful jawbone shared many features with those of bone-crunching spotted hyenas (Crocuta crocuta), according to the study. While this suggested the canid also could crush bones, scientists still couldn't be sure that was true, study co-author Jack Tseng, a functional anatomist at the University at Buffalo, told Live Science in an email. [10 Extinct Giants That Once Roamed North America]

"You could say we were scientifically constipated," Tseng said.

However, the floodgates were opened with the discovery of a cache of coprolites — 14 pieces of fossilized poop — at a site in California's Mehrten Formation. The location dates to the late Miocene epoch, about 5.3 million to 6.4 million years ago, and is known for being rich in Borophagus fossils; the coprolites, which are much rarer than bones, are thought to be about 2 million years old, the study authors reported.

Using micro-computed X-ray tomography (micro-CT) scans to peer inside the ancient poop, the researchers discovered plenty of bone splinters and fragments in all of the specimens, adding up to an average of 5 percent of the coprolites' mass.

"Rarely do paleontologists get the chance to validate our skull-centric research using the other end," Tseng said. And in this instance, the coprolites also told the researchers that Borophagus' eating habits didn't resemble spotted hyenas' as much as they'd thought.

Spotted hyenas thoroughly digest swallowed bones; consequently, when they poop, they produce "mochi-like balls of feces that are full of bone powder," Tseng said. Borophagus poop, on the other hand, held fragments of undissolved bone, suggesting that while the extinct dogs may have swallowed bones like spotted hyenas, they digested them like striped hyenas (Hyaena hyaena) and brown hyenas (Hyaena brunnea), which don't process bones as efficiently as their spotted cousins, Tseng said.

As well as providing clues to Borophagus' diet and digestion, the fossilized poo also testified to how they may have lived. Coprolites were found in communal "latrines" used by multiple individuals, suggesting Borophagus were social, territorial animals, according to the study. Modern hyenas, which are also social hunters, offer a glimpse of how that behavior might be linked to bone crushing after a successful hunt, study lead author Xiaoming Wang, a curator in the Department of Vertebrate Paleontology at the Natural History Museum in Los Angeles, told Live Science in an email.

"While social hunting helps in overcoming large prey, once the prey is secured, the feeding itself is also highly competitive. So competitive, in fact, that individual hyenas have no time to chew their meat, and they simply break down the prey in large enough chunks and quickly swallow bones and meat together, in order to grab the next bite of food," Wang explained.

The findings were published online May 22 in the journal eLife.

Original article on Live Science.

Here are some things that are true about tardigrades: They're tiny, measuring between 0.05 millimeters to 1.2 mm (0.002 to 0.05 inches) long, right on the edge of visible. They're not one species, but a whole phylum of animals. (A phylum is a broad category; There are just 32 phyla in the animal kingdom.) They're incredibly common in wet soil. And they're among the hardiest creatures on Earth, able to survive dehydration, blasts of radiation, and intense swings in temperature.

Here's something else that's apparently true about them: They take great big poops.

Tessa Montague, a recent PhD graduate of Harvard's Department of Molecular and Cellular Biology, posted a video on Twitter of a tardigrade, well, taking a huge poo. The little animal has a large dark mass in its digestive tract, about a third of its total length. And in the remarkably clear video Montague posted, the poop passes out of the tardigrade's rectum, then it kicks all eight of its little legs to squirm away from it. Its two rear legs scrabble at the poo as it moves.

Live Science reached out by email with a few questions for Montague about the video and tardigrade poop, and her answers are printed below, lightly edited for clarity.

Live Science: About how often do tardigrades poop?

Tessa Montague: I have no idea. The scientist who provided me with the tardigrades, Bob Goldstein (a prof at UNC Chapel Hill), had not yet borne witness to tardigrade defecation when I showed him this video, so that would suggest this kind of pooping doesn’t happen very often.

LS: Are the poops always this big compared to their bodies?

Montague: Yes (n=2) [this means she's only seen two examples]. There is one other tardigrade pooping video online, and that poop was also very large. Interestingly, that tardigrade seemed to struggle to relieve itself more than mine did. There might be a technical explanation: My tardigrade was lightly pressed between two cover slips to keep it from moving out of the frame of the microscope, so it’s possible that by doing this, I added a little extra oomph to the poop release. Hopefully the tardigrade felt as relieved as I did watching it.

LS: Do we know how much they weigh?

Montague: No, afraid not. The tardigrade is about 0.2 mm (0.008 inches) long, so perhaps you could calculate an approximate biomass for the poop.

LS: What are the poops made up of?

Montague: Tardigrades eat lichens, algae etc. so the poop was probably partially digested lichen. I captured this footage using a phase contrast setting on the microscope, so it’s in black and white. In full technicolor, the poop is bright green!

LS: Is there anything else you think readers should know about tardigrades and their poops?

Montague: Apparently some tardigrades only poop when they molt. Not this guy. This species molts when it lays eggs.

Originally published on Live Science.

Every day, thousands of hippos come to Kenya's Mara River. But they aren't there just to cool down — they also come to poop.

As the hippos wallow, they collectively expel considerable quantities of waste — an estimated 9.3 tons (8,500 kilograms) of excrement each day, scientists recently reported. Large animals' feces nourish ecosystems by providing vital nutrients for smaller organisms, but the sheer volume of hippopotamus dung poses a deadly challenge to fish that live downstream from these communal toilets, leaving the fish gasping for oxygen under a deluge of dissolved hippo poo, according to a new study. [How Much of the Ocean Is Whale Pee (and Worse)?]

Approximately 4,000 hippos live along the Mara River, gathering in an estimated 171 pools to wallow and defecate, the study authors reported. During the dry season, river levels decline and hippo pools shrink, leading to packed gatherings with more animals — and more poop piling up at the bottom of these pools. As the feces decompose, associated microbes hoover up oxygen in the water and produce chemicals that include ammonium and hydrogen sulfide, which can be lethal to fish.

Eventually, hippos' group toilets are "flushed" as powerful, episodic rainstorms wash away the chemical soup of their fecal deposits. These so-called "flushing flows" carry the muck downstream, where the infusion of feces-rich and oxygen-poor water suffocates fish populations, study co-author Emma Rosi, a freshwater ecologist at the Cary Institute of Ecosystem Studies in New York, said in a statement.

"This sudden pulse of deoxygenated water can cause temporary hypoxia [oxygen deficiency] and fish kills," Rosi said.

Over three years, the scientists observed 55 flushing flows at hippo pools in the region, noting their impact on water conditions farther down the river. They found that the amount of dissolved oxygen in downstream water plummeted after 49 of those flows, and 13 times it dropped low enough to cause mass fish die-offs, the researchers wrote in the study.

In fact, the number of fish kills during that time span could be even higher; hungry scavengers likely took advantage of fish deaths in remote locations and gobbled up the evidence before the aquatic carnage could be documented, the study authors reported.  

The findings were published online yesterday (May 16) in the journal Nature Communications.

Original article on Live Science.

About 500 million years ago, a large predatory sea worm munched on some dinner and left behind a pile of turds. Then, the worm left its burrow on the seafloor, and some shelled critters came along, poked at the droppings and died — fossilized for eternity around the poopy picnic.

Researchers realized they were looking at a Cambrian period buffet when they discovered a fossil containing the sea worm's fossilized excrement and the remains of conically shelled sea critters known as hyoliths, according to a new study published online yesterday (April 3) in the journal Palaios.

In addition to this remarkable find, the researchers unearthed other sea worm coprolites (fossilized poop) that other Cambrian creatures, including trilobites, had fed on. These animals were "opportunistic coprovores [dung eaters] drawn to the organic-rich fecal mass," the researchers wrote in the study. [Cambrian Creatures Gallery: Photos of Primitive Sea Life]

The scientists found the ancient burrows in the Rockslide Formation of the Mackenzie Mountains in northwestern Canada. They noticed the ancient sea worm's burrows in a layer of "greenish, thinly laminated, locally burrowed, slightly [chalky] mudstone," the researchers wrote in the study.

"This is rare, because feces decompose very easily — it's not a very stable product from animals," study lead researcher Julien Kimmig, the collections manager at the Kansas University Biodiversity Institute and Natural History Museum, said in a statement. "These were preserved because the worms lived in burrows about 4 inches [10 centimeters] deep. They were hunting out of these burrows. We have something that acted very similar to a modern Bobbit worm."

In fact, the 500-million-year-old sea worm might be a distant relative of today's Bobbit worm (Eunice aphroditois), which buries itself under sediment on the seafloor and ambushes prey.

"Bobbit worms are big worms that live in the ocean today," Kimmig said. "They prey on fish, live in burrows [and] have really big predatory appendages, and they hide in the burrow until a fish or other prey comes by — then they grab it, drag it into their burrow and eat it."

Even though the researchers didn't find the remains of the mysterious Cambrian sea worm, its fossilized feces and burrows suggest that it was "likely one of the biggest predators in its environment," ranging from 6 inches to 12 inches (15 to 30 cm) long, Kimmig said. It was as wide as a penny, with a 0.75-inch (2 cm) diameter, he added.

The finding shows how ancient food webs worked, but many questions remain, Kimmig and study co-researcher, Brian Pratt, a professor of geological sciences at the University of Saskatchewan, who found the fossil site in 1983 during his doctoral research, said in the statement.

"This tells us [that] animals develop a variety of feeding strategies early on, and they developed them fairly quickly," Kimmig said. "[But] we have a lot to learn about the early ecosystems and how they forced animals to adapt. When you have different predators along the open sea bottom, if you're not careful, you'll get eaten fairly easily."

Original article on Live Science.

A person's accomplishments accumulate over years and decades. Something else accumulates, too — their poop.

The quantities of poop that people leave behind during an individual bathroom break can vary widely, depending on age, body weight, diet, exercise and other factors.

But how much poop does the average person produce in their lifetime? [The Poop on Pooping: 5 Misconceptions Explained]

• Related: Why is your poop brown?

Moving one's bowels is part of the normal digestive process for most animals; after nutrients are extracted from food and liquid, waste is eliminated as urine and feces. Human stool, when healthy, is usually made up of about 70-percent solids and 30-percent fluids, Kim Barrett, a professor of medicine at the University of California, San Diego, told Live Science. Personal bowel habits notwithstanding, on average, both men and women move their bowels about once per day and produce a daily average of 14 to 17 ounces (400 to 500 grams) of feces, Barrett said.

Researchers have even identified the speed at which humans generally produce their poo: about 0.8 inches (2 centimeters) per second, Live Science previously reported. Constipation — being unable to move one's bowels — can lead to longer, or more uncomfortable bathroom sessions. However, the amount of time a person typically dedicates to unobstructed defecation is about 12 seconds per stool, and is uniform across many animal species regardless of their size, according to David Hu, an associate professor of mechanical engineering and biology at the Georgia Institute of Technology and Patricia Yang, a Georgia Tech doctoral candidate in mechanical engineering.

The amount of poo produced by a single person starts to add up when you calculate poop production over years and decades.

Starting with an average daily amount of about 14 ounces (400 grams), the total poop production in a week's time would be about 6 lbs. (2.8 kilograms). In a year, a single person would yield about 320 lbs. (145 kg) of poop — just a little more than an adult panda weighs.

In the U.S., the average life expectancy for men is about 76 years old, and for women, it is around 81 years old. Therefore, a man living to age 76 would produce about 24,320 lbs. (11,030 kg) of poop over his lifetime, and a woman living to age 81 would produce about 25,920 lbs. (11,757 kg) — so a lifetime of a woman's poop weighs about as much as three adult male hippos.

Recently, the stark reality of how much poop humans can produce prompted action from officials at Denali National Park and Reserve in Alaska. Years of unregulated pooping by visitors to Denali, North America's tallest mountain, left an estimated 152,000 to 215,000 lbs. (69,000 to 98,000 kg) of feces deposited on the mountain between 1951 and 2012.

Another unpleasant reality is that 4.5 billion people around the world do not have access to household toilets that safely dispose of their waste, according to the United Nations. And each year, over 200 million tons (181 million metric tons) of human waste goes untreated, with more than 90 percent of sewage in the developing world released directly into oceans, lakes and rivers.

At least 1.8 billion people worldwide depend on a drinking water source that is contaminated by fecal residue; poor sanitation leads to disease outbreaks and public health crises that affect millions of people each year — many of them children. However, improving access to clean water and implementing better sanitation practices, such as feces containment and treatment that enables its safe disposal, could prevent approximately 842,000 deaths each year, according to reports from the World Health Organization and the United Nations Children's Fund.

Original article on Live Science.

A man in England is refusing to poop, allegedly to conceal evidence of drug dealing.

The police officers who arrested the 24-year-old on Jan. 17 said they saw him swallowing what appeared to be drugs. According to the BBC, prosecutors now say he's refusing to eat very much in order to prevent himself from pooping out the evidence. He's allegedly gone 43 days without evacuating his bowels.

So what happens when you refuse to poop? Not usually anything good, according to gastroenterologist Ian Lustbader of New York University Langone Health.

"Birds gotta fly, fish gotta swim and colons gotta poop," Lustbader told Live Science. [5 Things Your Poop Says About Your Health]

Fecal retention

Voluntarily withholding stool for long periods of time is rare, Lustbader said. Typically, people with chronic constipation or bowel-motility problems desperately want to defecate. (Bowel motility refers to how well the digestive system can move contents through it.) If they're eating and not pooping, the colon can become dangerously distended, a condition called "megacolon." The feces can become hard and impacted, and the bowel can actually rupture. According to the book "Management of Functional Gastrointestinal Disorders in Children: Biopsychosocial Concepts for Clinical Practice" (Springer, 2014), the colon can grow so large that it can extend up into the rib cage.

It's not clear what the world record for not pooping is, but the book on gastrointestinal disorders includes an abdominal X-ray of a 13-year-old with "functional fecal retention syndrome" who could not recall pooping in the past year. This syndrome, mostly seen in children, occurs when a patient becomes frightened of pooping, perhaps because past attempts have been painful. The patient tightens the pelvic muscles and buttocks when the urge to defecate strikes. Small amounts of liquid feces may sneak past the growing mass of solid stool, which becomes larger and more potentially painful to pass by the day. Kids can retain their feces for weeks or months. Symptoms include pain, irritability and loss of appetite. Treatment includes laxatives and stool softeners.

Colon slowdown

In the case of the man in England, refusing food would indeed dramatically delay the urge to defecate, Lustbader said, but that's a temporary solution: Eventually, malnutrition will become a problem. The best analogy is patients who can't swallow for neurological reasons, Lustbader said; they can survive on intravenous nutrition for a while, but intravenous feeding is hard to maintain over long periods.

If the man did swallow drugs, Lustbader said, he risks having the packaging they're wrapped in break down and having the drugs seep into his system. This could cause an overdose. On the other hand, Lustbader said, if the amount of drugs were small, the body could potentially absorb the seepage, and the man might successfully hide the evidence — unless the authorities test his urine. [What's in Urine? 3,000 Chemicals and Counting]

Holding back the urge to poop could also potentially damage the feedback mechanism that keeps the bowel moving smoothly, Lustbader said.

"If you constantly suppress the need to poop, you do run the risk of altered bowel motility in the future, or possibly needing laxatives or other things to stimulate your colon to work again," he said.

Even with no food whatsoever, he said, the bowel is likely to produce a little bit of runny discharge. The intestinal lining produces mucous and fluids, so the suspected drug dealer's colon is not likely to stay completely empty. The man is scheduled for his seventh court hearing on Friday (March 2), according to the BBC.

"We're going to see who wins," Lustbader said. "The system or the colon."

Original article on Live Science.

Why climb Denali? Because it's there.

Why carry your poop 14,000 feet (4,200 meters) up the mountain in a glorified coffee can before casting it into a deep crevasse? Because you have to.

According to a new set of waste-management regulations proposed this year, climbers who want to reach the summit of Alaska's Denali National Park and Preserve may dispose of their poop in just one location on the mountain and one location about 100 miles (160 kilometers) away, the Associated Press reported. The proposed rule changes were motivated by more than a decade of research conducted by National Park Service (NPS) researchers who found that glacial melt on the mountain is getting close to contaminating nearby water sources with distressing amounts of human fecal bacteria.

Standing about 20,000 feet (6000 m) above sea level, Denali (formerly known as Mount McKinley) is North America's tallest land-based mountain. More than 1,000 climbers visit every year, and according to Michael Loso, a glacier geologist at the NPS, these intrepid visitors leave behind more than 4,400 lbs. (2 metric tons) of human waste every year. [Inside The World's Tallest Mountains]

That's a lot of poop — and the numbers look even worse when you take a historical view. According to an NPS report, climbers left behind somewhere from 152,000 to 215,000 lbs. (69 to 97 metric tons) of feces on the mountain between 1951 and 2012. Most of this waste is confined to crevasses on the West Buttress of Kahiltna Glacier, a popular pathtoward Denali's summit.

Park officials have been conscious of the waste problem for a while. Beginning in 2007, new NPS regulations asked each climber trekking above the mountain's 14,200-foot (4,300 m) Camp Four to capture their waste in a Clean Mountain Can, a 1.88-gallon polyethylene container designed to hold 10 to 14 bowel movements.

Climbers were encouraged to empty these cans into deep crevasses across the glacier, with the expectation that the waste would freeze and decompose.

According to Loso's research, however, the poop isn't decomposing. As part of his decade-long waste-management research, Loso buried human waste in the glacier, then dug it up a year later. He determined that crevassed stool was not reaching the subfreezing temperatures or being exposed to the ultraviolet light necessary to kill bacteria.

And thanks to glacial melt, this contaminated waste could one day enter the Alaskan watershed.

Denali's West Buttress climbing route is located in Kahiltna Glacier's accumulation zone, the region of a glacier where annual snowfall exceeds annual melt. Because of this, crevassed waste gets buried deeper and deeper under snow every year, where it will eventually turn to ice and flow downhill. Inevitably, this cache of old waste will melt out at the glacier's surface, possibly contaminating the Kahiltna Riverthat flows from the glacier's melt zone.

Indeed, Loso and his colleagues found trace amounts of fecal bacteria in Kahiltna River during water tests conducted in 2011 and 2012. According to the NPS, the contamination was very small and still within Alaska's state water-quality standards. Regardless, Loso's findings motivated park officials to revise their waste-management rules.

According to the proposed rule changes, climbers may dispose of the waste stored in their Clean Mountain Cans at one of two places: at the Talkeetna Ranger Station, located about 100 miles (160 km) south of the entrance to Denali National Park, and in one crevasse located above the 14,200-foot (4,300 m) Camp Four. Dung dumped into this crevasse will drop down a huge cliff and is "likely to be pulverized" in the fall, the AP reported.

Originally published on Live Science.