A rare ant species in Japan has no males or workers ‪—‬ only queens, scientists have found. These ant queens live parasitically in the nests of another ant species and reproduce asexually to create clone queens to take over other nests.

The parasitic ant, Temnothorax kinomurai, is the "first known species with only queens," said Jürgen Heinze, a biologist at the University of Regensburg in Germany, and co-author of a new study describing the findings.

Most ants live in regimented, closely related societies in which queens retain sperm cells from when they mated before founding the colony. They use these sperm cells selectively to either lay fertilized eggs that will become female workers or queens, or unfertilized eggs that develop as short-lived males.

But there are also parasitic queens that infiltrate the colonies of other species and take them over, often getting the workers to serve them and rear their offspring until their own brood has taken over.

Keiko Hamaguchi, a biologist at the Kansai Research Center in Kyoto, Japan, and her colleagues have been investigating T. kinomurai, which has been found in only nine locations in Japan. The ant was suspected to operate differently and produce just queens without any workers or males, but it wasn't known for sure.

Young T. kinomurai queens invade the nests of a related species, Temnothorax makora, stinging the host queen and the most aggressive workers that try to stop the coup. If the takeover works, the surviving workers raise the alien queen's young.

"T. kinomurai needs the host workers for foraging and brood care and cannot produce offspring without them," Heinze told Live Science via email.

To work out what happens, Hamaguchi's team collected six colonies run by T. kinomurai queens and kept them in nest boxes in the lab. From these colonies, they reared 43 offspring, none of which were males, according to examination of the genitals, or workers, which would be smaller. All were queens.

When presented with new potential host T. makora colonies, seven of the 43 offspring, which had never mated, succeeded in coup attempts. This is in line with the typical high failure rate of the risky business of founding a parasitic colony. The seven queens produced a total of 57 offspring, which were also all queens. The findings were published Feb. 23 in the journal Current Biology.

Queens of some ant species can clone themselves through asexual reproduction, known as parthenogenesis. Other ants exploit social parasitism, hijacking the workforce of unrelated colonies to rear their own offspring.

"Yet, until now, no species had been shown to merge both strategies, despite the intuitive evolutionary logic behind such a combination," Jonathan Romiguier, an evolutionary biologist at the University of Montpellier in France who wasn't involved in the work, told Live Science via email.

"Given that there are over 15,000 ant species out there, this is quite unusual," added Daniel Kronauer, a biologist at The Rockefeller University in New York who wasn't involved in the study.

The benefits of sexual and asexual reproduction are normally finely balanced, he said. Asexual reproduction can allow an organism to maximize its own genetic contributions to the next generation by producing genetically identical daughters, and asexual species can often outcompete their sexual counterparts because they don't have to invest energy and resources into finding mates and producing males.

But sexual reproduction produces genetically diverse workers, which can be beneficial for an ant colony when it comes to pathogen defense and division of labor.

However, given that T. kinomurai queens don't produce workers anymore, those benefits have disappeared, Kronauer told Live Science. "This could shift the balance in favor of asexual reproduction and, ultimately, the loss of males," he said.

By adding a handful of live ants to warm milk, a group of anthropologists and food scientists investigated how to make "ant yogurt" — and they ended up learning that it has the same ingredient as a popular type of bread.

The bacteria in the "ant yogurt," which they made using a traditional Balkan method, is a strain that's commonly used as a sourdough starter today, the team found. They then served the yogurt to patrons at a restaurant to showcase historical methods of fermenting food.

The process behind concocting this ant delicacy is dramatically different from how the fermented dairy food is industrially made today, the researchers wrote in a study published Friday (Oct. 3) in the journal iScience.

"Today's yogurts are typically made with just two bacterial strains," study co-author Leonie Jahn, a researcher at the Technical University of Denmark, said in a statement. The strains, Lactobacillus bulgaricus and Streptococcus thermophilus, are introduced to warm milk as a bulk starter. The bacteria ferment the sugars in the milk, producing lactic acid, which lowers the pH and increases the acidity of milk, causing the milk to coagulate. This also gives yogurt its consistency and flavor.

"If you look at traditional yogurt, you have much bigger biodiversity," Jahn said, because various bacterial strains impart different flavors and textures to the food.

Study co-author Sevgi Mutlu Sirakova, a doctoral student at Ludwig Maximilian University of Munich, previously gathered oral histories from people in Turkey and Bulgaria that described different methods of creating yogurt, including the use of red wood ants (Formica sp.) to kick-start the process. The researchers visited Sirakova's family village in Bulgaria, where locals recalled the tradition of using ants to make yogurt.

"We dropped four whole ants into a jar of warm milk by the instruction of Sevgi's uncle and community members," study co-author Veronica Sinotte, a microbiologist at the University of Copenhagen, said in a statement. After keeping the jar of milk warm in the ant mound overnight, they tried the yogurt that had formed — and described it as "slightly tangy" and "herbaceous."

After making the ant yogurt, the team studied it to understand the role of the ant "holobiont," which includes both the ant and the microbial communities in and on the creature.

Chemical analysis of the yogurt revealed that the dominant bacterium responsible for fermentation was Fructilactobacillus sanfranciscensis, a species that is much better known as a key ingredient in sourdough bread. Additionally, they discovered abundant formic acid in the yogurt. Wood ants produce large amounts of formic acid in their venom gland, and they can spray it as a defense mechanism. The formic acid gave the yogurt a unique taste and texture.

"This study highlights ants as a reservoir of bacteria with potential for food fermentation, and the importance of both ant biodiversity and traditional practices in maintaining this potential," the researchers wrote in the study.

To further test the culinary possibilities of ant yogurt, the researchers partnered with Alchemist, a 2 Michelin-star restaurant in Copenhagen. The chefs created three new dishes from the ant yogurt: an ant-shaped ice cream sandwich, tangy cheeses, and a "milk wash cocktail" from a recipe dating back to the early 1700s.

But amateur cooks should not try this at home, the researchers warned, because ants can harbor parasites. The researchers used a microbiology-grade sieve to remove any potential parasites before passing the yogurt to the restaurant.

The use of ants in yogurt making remains widespread in Turkey and Bulgaria today, and now scientists understand exactly how the ants react with the milk to produce yogurt.

"I hope people recognize the importance of community and maybe listen a little closer when their grandmother shares a recipe or memory that seems unusual," Sinotte said.

Editor's Note: This story was updated at 10:05 a.m. ET on Oct. 6 to note that lactic acid lowers the pH and increases the acidity of milk, causing milk to coagulate.

Invasive ants whose sting can cause fatal allergic reactions in humans are surging across the U.S. Southeast and beyond — and experts are growing increasingly alarmed.

Asian needle ants (Brachyponera chinensis) went relatively unnoticed for many years following their introduction to the U.S. roughly a century ago, but entomologists recently documented their spread from a handful of southeastern states to New England and the Midwest. Asian needle ants are capable of invading many of North America's temperate forests, according to the U.S. Department of Agriculture (USDA), and with the spring swarming season about to start, there's a chance that these ants could trigger medical emergencies up and down the country.

"We are now considering it a medically important pest," Dan Suiter, a professor of urban entomology at the University of Georgia, told Fox Weather on April 29.

Suiter said he recently noticed an uptick in Asian needle ant stings. In 2024, he received three calls from people who suffered anaphylaxis as a result of Asian needle ant stings — a high number compared with previous years, he told Fox Weather.

Anaphylaxis is an acute, whole-body allergic reaction that happens very quickly in some people after exposure to certain medicines, foods or insect stings. Symptoms include a rapid and weak pulse, a skin rash, nausea and vomiting, according to the Mayo Clinic. Anaphylaxis can be fatal, because it causes the immune system to release a flood of chemicals that constrict the airways, which prevents breathing. These chemicals also trigger a dangerous drop in blood pressure, increasing the risk of cardiac arrest.

Related: 'The parasite was in the driver's seat': The zombie ants that die gruesome deaths fit for a horror movie

Ants are common pests, but "it gets a little bit more serious when the sting of an insect can be life-threatening to people who suffer anaphylaxis," Suiter said. It is unclear how many people have died from Asian needle ant stings globally and in the U.S. since their introduction.

Asian needle ants are small, shiny, dark brown-to-black ants native to China, Japan and Korea. They were first discovered in the U.S. in 1932 following introduction via shipping — but by that point they were already present in at least three southeastern states, according to the USDA.

Asian needle ants are not aggressive or defensive of their nests in the way that fire ants (Solenopsis) are, but they will deliver a venomous sting if they get trapped inside human clothing or beneath someone's hand. People in affected areas should look out for these ants' light-orange antennae and leg-tips, although it takes an experienced eye to positively identify the species, according to the USDA.

There's no way to predict who will get anaphylaxis after an Asian needle sting, but people who react adversely to other insect stings or carry an EpiPen should be especially cautious of these ants, Suiter said. Regardless of whether someone is vulnerable to anaphylaxis, Asian needle ant stings cause severe pain at the site of the sting, according to the USDA.

There have been some control measures to limit the spread of Asian needle ants, but these efforts are extremely costly, according to the USDA. Asian needle ants typically nest beneath logs, stones and leaf litter, but they may also be found in wood piles. They do not form trails like other ants but instead walk alone and chaotically, Suiter said.

"This critter kind of wanders around," he said. "It looks lost."

A newly discovered "hell ant" fossil may be the oldest ant ever found, scientists say.

This fossilized insect was unearthed in what is now northeastern Brazil and lived around 113 million years ago, during the Cretaceous period (145 million to 66 million years ago), according to a new study published April 24 in the journal Current Biology.

"Our team has discovered a new fossil ant species representing the earliest undisputable geological record of ants," study co-author Anderson Lepeco, a researcher at the Zoological Museum of the University of São Paulo in Brazil, said in a statement. "What makes this discovery particularly interesting is that it belongs to the extinct 'hell ant,' known for their bizarre predatory adaptations."

The newly discovered ancient ant species, which researchers have named Vulcanidris cratensis, had scythe-like, upward-facing jaws, which it may have used to seize and impale its prey. "Despite being part of an ancient lineage, this species already displayed highly specialized anatomical features, suggesting unique hunting behaviors," Lepeco said.

There are more than 12,000 species of ants on Earth today, and they can be found in diverse environments, from rainforests to deserts. They belong to the family Formicidae, which is part of the order Hymenoptera (which also includes bees and wasps). Ants are thought to have evolved from wasp-like ancestors around 140 million years ago.

Haidomyrmecinae, also called "hell ants," were an extinct subfamily of ancient ants that lived during this period. A handful of previous hell ant species have been discovered in amber fossils in Myanmar, France and Canada, dating back around 100 million years, which until now were the earliest known ant fossils.

These hell ants had a bizarre head and jaw structure unlike anything seen in modern ants, with upward-curved jaws instead of inward- or downward-curved jaws like modern ants, which could snap shut vertically. Many species also had horn-like projections above their mouths, which are thought to have clamped against the jaws to trap prey. One previously discovered 99 million-year-old fossil even captured a hell ant in the act of killing prey, frozen in amber mid-strike.

The newfound species of hell ant was preserved in limestone in the Crato Konservat-Lagerstätte geological formation in Brazil, which was once located in the north of the ancient supercontinent Gondwana. The fossil was then rediscovered by researchers among a collection housed at the Zoological Museum of the University of São Paulo.

"When I encountered this extraordinary specimen, we immediately recognized its significance, not only as a new species but as potentially the definitive evidence of ants in the Crato Formation," Lepeco said. "This finding highlights the importance of thorough examination of existing collections — private or in museums — and brings a spotlight to Brazilian paleontology and the underexplored fossil insect fauna of the country."

At 113 million years old, this ant is the earliest ant specimen ever discovered, and is also the first hell ant to be discovered preserved in rock, Lepeco noted.

Using micro-computed tomography imaging, a technique that uses X-rays to see inside an object, the researchers confirmed that the ant species was a hell ant, identifying the characteristic upward-facing jaws.

The fact that this ant is the earliest ant ever found and already possessed the same iconic scythe-like jaws as other hell ants, suggests that these traits evolved early after ants first appeared.

The researchers also discovered that this newfound species of ant was likely closely related to other hell ants found preserved in amber in Myanmar, meaning that ants were already widely distributed across the globe sooner than scientists had assumed.

"Finding such an anatomically specialized ant from 113 million years ago challenges our assumptions about how quickly these insects developed complex adaptations," Lepeco said. "The intricate morphology suggests that even these earliest ants had already evolved sophisticated predatory strategies significantly different from their modern counterparts."

Zombies are among us. And these tiny undead creatures are everywhere. In this excerpt from "Rise of the Zombie Bugs" (Johns Hopkins University Press, 2025), author Mindy Weisberger examines the very grisly end for worker ants that get zombiefied by the decapitating fly Pseudacteon wasmanni.

Scientists first described the gruesome habits of ant decapitators in the phorid genus Pseudacteon more than 90 years ago, from observations among ant populations in Europe, South America, and the United States. A female fly begins by staking out a worker ant — carefully keeping her distance at first, as she is no bigger than her target's head.

To scientists observing phorids in the field, "they appear as minute, fuzzy specks as they hover over host ants," Lloyd Morrison, an ecologist for the National Park Service, wrote in a guide to insect parasitoids in North America.

Females don't have a lot of time to be choosy about their hosts, as adult flies live only for about a week or less in the wild. When the female fly sees an opening, she darts in and lays an egg inside the ant's thorax — one and done — in less than a second (analysis of the female reproductive system in the phorid fly Pseudacteon wasmanni revealed that eggs are torpedo-shaped and measure 130 micrometers long, or about 0.005 inches).

A single Pseudacteon female can produce from 200 to nearly 300 eggs, and in a single hour she may make more than 100 parasitizing attempts (though she only lays one egg per host).

Newly parasitized workers "frequently appear stunned after an oviposition strike," U.S. Department of Agriculture entomologist Sanford Porter wrote in Florida Entomologist, and the ants "often stilt upon their legs for a few seconds to a minute before running away."

These egg-laying attempts don't all succeed; indeed most of them flop. In laboratory experiments, when Pseudacteon females tried to implant an egg in an unwilling ant, they failed at least 65% of the time. But when an egg does manage to end up inside an ant, its host enters the realm of the walking dead. Once the egg hatches, the ant has only a few weeks of life before it succumbs to the manipulations of its attacker, stumbling away from its home and family and then undergoing decapitation from the inside out.

Within days after hatching, the phorid larva migrates from the thorax into the ant's head; little is known about how the parasitoid avoids being destroyed by the ant's immune system, but one possibility is that moving quickly into the host's head may help the larva evade an immune response. For the duration of the larva's second instar — about two to three weeks — it makes itself comfortable in the ant's head cavity, sipping on hemolymph.

This liquid nutrition is all the larva needs until it reaches its third instar. For an infected ant during those initial honeymoon weeks, despite carrying and nourishing a growing parasite inside its head, life is pretty much business as usual; the ant looks and behaves normally, according to scientists with the Louisiana State University (LSU) College of Agriculture.

Through "intensive observation" of ant parasitism by the phorid fly Pseudacteon tricuspis, LSU researchers found that a parasitized ant stayed with its nest mates until about 8 to 10 hours before the larva in its head was ready to pupate. It would then depart the nest on what appeared to be a normal foraging expedition, alongside its non-parasitized sisters. But for the zombified ant, this final excursion was a one-way trip.

Once the ant turned its back on the colony and walked away, it was on a death march. And the parasite was in the driver's seat. "Parasitized ants were highly mobile after they left the nest and ultimately entered the thatch layer at the soil surface," the scientists reported. "The term 'zombie' fire ant workers was coined to characterize the behavior while under parasitoid control."

Finally, the phorid larva is ready for its metamorphosis. It releases an enzyme that degrades membranes in the wandering ant's exoskeleton, causing the ant to stop walking and eventually collapse. The ant's head loosens from the body, as does the first pair of legs; other legs may be affected, too. Its mandibles weaken, rendering it unable to bite or burrow. As for the larva, it indulges a new appetite for solid food; namely, ant head tissue. You can probably guess where this is headed; the ant's hollowed-out, larvae-stuffed head falls off (the ant, unsurprisingly, is already dead by now, even though its legs are often still twitching as its head rolls away).

The parasitoid, however, is just fine. It finishes off the last of the tasty bits inside the decapitated ant head and pushes the mandibles out of the way — the ant's no longer using them, after all — and then the larva wriggles into position so that its first three pupal segments are stuffed into the gap where the ant's mouthparts used to be.

These segments harden and darken, becoming a tough, protective plate that's roughly the same color as the ant's exoskeleton, and two hairlike breathing "horns" extend from the pupa out on either side of the ant's mouth opening. Other parasitoid insects keep their zombie host alive until the larva's metamorphosis is over, but phorids pupate unguarded inside their dead hosts' disembodied heads.

However, the exoskeleton of an ant's head is extremely hard — tougher than other parts of its body — and therefore lends extra protection to the pupating larva, Brown says. Two to six weeks later, depending on air temperature and species size, the adult phorid fly is ready to pop out from inside the detached ant head, like the goddess Athena of legend springing fully grown from the head of her father, Zeus.

Only, this newborn is a lot smaller than an ancient Greek deity and has more legs than most. A few hours after emerging, the adult phorid fly is ready to mate — and continue its head-splitting reproductive cycle.

Excerpted from Rise of the Zombie Bugs: The Surprising Science of Parasitic Mind-Control by Mindy Weisberger. Copyright 2025. Published with permission of Johns Hopkins University Press

Exploring anywhere on Earth, look closely and you'll find insects. Check your backyard and you may see ants, beetles, crickets, wasps, mosquitoes and more. There are more kinds of insects than there are mammals, birds and plants combined. This fact has fascinated scientists for centuries.

One of the things biologists like me do is classify all living things into categories. Insects belong to a phylum called Arthropoda — animals with hard exoskeletons and jointed feet.

All insects are arthropods, but not all arthropods are insects. For instance, spiders, lobsters and millipedes are arthropods, but they're not insects.

Instead, insects are a subgroup within Arthropoda, a class called "Insecta," that is characterized by six legs, two antennae and three body segments — head, abdomen and the thorax, which is the part of the body between the head and abdomen.

Most insects also have wings, although a few, like fleas, don't. All have compound eyes, which means insects see very differently from the way people see. Instead of one lens per eye, they have many: a fly has 5,000 lenses; a dragonfly has 30,000. These types of eyes, though not great for clarity, are excellent at detecting movement.

What is a species?

All insects descend from a common ancestor that lived about about 480 million years ago. For context, that's about 100 million years before any of our vertebrate ancestors — animals with a backbone — ever walked on land.

A species is the most basic unit that biologists use to classify living things. When people use words like "ant" or "fly" or "butterfly" they are referring not to species, but to categories that may contain hundreds, thousands or tens of thousands of species. For example, about 18,000 species of butterfly exist — think monarch, zebra swallowtail or cabbage white.

Basically, species are a group that can interbreed with each other, but not with other groups. One obvious example: bees can't interbreed with ants.

But brown-belted bumblebees and red-belted bumblebees can't interbreed either, so they are different species of bumblebee.

Each species has a unique scientific name — like Bombus griseocollis for the brown-belted bumblebee — so scientists can be sure which species they're talking about.

Related: What is a species?

Quadrillions of ants

Counting the exact number of insect species is probably impossible. Every year, some species go extinct, while some evolve anew. Even if we could magically freeze time and survey the entire Earth all at once, experts would disagree on the distinctiveness or identity of some species. So instead of counting, researchers use statistical analysis to make an estimate.

One scientist did just that. He published his answer in a 2018 research paper. His calculations showed there are approximately 5.5 million insect species, with the correct number almost certainly between 2.6 and 7.2 million.

Beetles alone account for almost one-third of the number, about 1.5 million species. By comparison, there are "only" an estimated 22,000 species of ants. This and other studies have also estimated about 3,500 species of mosquitoes, 120,000 species of flies and 30,000 species of grasshoppers and crickets.

The estimate of 5.5 million species of insects is interesting. What's even more remarkable is that because scientists have found only about 1 million species, that means more than 4.5 million species are still waiting for someone to discover them. In other words, over 80% of the Earth's insect biodiversity is still unknown.

Add up the total population and biomass of the insects, and the numbers are even more staggering. The 22,000 species of ants comprise about 20,000,000,000,000,000 individuals — that's 20 quadrillion ants. And if a typical ant weighs about 0.0001 ounces (3 milligrams) — or one ten-thousandth of an ounce — that means all the ants on Earth together weigh more than 132 billion pounds (about 60 billion kilograms).

That's the equivalent of about 7 million school buses, 600 aircraft carriers or about 20% of the weight of all humans on Earth combined.

Many insect species are going extinct

All of this has potentially huge implications for our own human species. Insects affect us in countless ways. People depend on them for crop pollination, industrial products and medicine. Other insects can harm us by transmitting disease or eating our crops.

Most insects have little to no direct impact on people, but they are integral parts of their ecosystems. This is why entomologists — bug scientists — say we should leave insects alone as much as possible. Most of them are harmless to people, and they are critical to the environment.

It is sobering to note that although millions of undiscovered insect species may be out there, many will go extinct before people have a chance to discover them. Largely due to human activity, a significant proportion of Earth's biodiversity — including insects — may ultimately be forever lost.

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

There's been a lot going on in animal news this year.

Perhaps the best animal story of 2024 came right at the end of the year, when orcas (Orcinus orca) started wearing salmon hats again after a 37-year hiatus from the fabulous fad. And while scientists don't really know why orcas are balancing dead fish on their heads, the best guess is there is so much of their favorite food — chum salmon (Oncorhynchus keta) — available, it's a way to save it for later.

But there was plenty of other news from the animal kingdom this year. We found out that female gibbons do the robot and "vogue" — but only if they're sure someone else is watching. Researchers aren't sure why the apes do it (the dancing was seen in wild and captive gibbons), but it seems to relate to sex, food and their social lives.

Speaking of food, we had two never-before-seen cases of predators eating each other. In the sea, a pregnant portbeagle shark (Lamna nasus) got gobbled up by another shark — likely a great white shark (Carcharodon carcharias) or a shortfin mako (Isurus oxyrinchus). And on land, a Burmese python (Python bivittatus) was seen feasting on an even bigger reticulated python (Malayopython reticulatus) from the tail up, while it was still alive. A Burmese python in Florida also swallowed a deer whole by stretching its mouth to almost the limit of what is physically possible for the species.

In the insect world, scientists discovered that ants carry out life-saving operations by performing amputations on injured nestmates — becoming the only known animal in the world other than humans to do so.

Cassius, the world's largest captive crocodile, died in November, having potentially reached the ripe old age of 120. He was captured in the Finniss River, near Darwin, Australia, in 1984 after he started eating livestock, attacking boat engines and fighting other crocodiles. Scientists are now studying his bones to find out exactly how old he was when he died.

And it wasn't just living animals making headlines. In August, Siberian gold miners accidentally stumbled upon the mummified remains of a woolly rhino (Coelodonta antiquitatis) with its horn and soft tissues still intact. A winemaker in Austria found hundreds of mammoth bones while renovating his cellar, and scientists performed an autopsy on a 44,000-year-old mummified wolf pulled from the permafrost.

Related: 35,000-year-old saber-toothed kitten with preserved whiskers pulled from permafrost in Siberia

Researchers in the U.K., meanwhile, discovered what could have been the biggest marine reptile ever found. This ichthyosaur, which lived 200 million years ago, is estimated to have been a whopping 82 feet (25 meters) long. Also from the age of the dinosaurs, palaeontologists in Morocco discovered a never-before-seen species of marine lizard with "dagger-like" teeth; and in Brazil, heavy rains exposed one of the oldest dinosaur skeletons ever discovered.

And where the living and long-dead collide, scientists now say the de-extinction of species like the woolly mammoth (Mammuthus primigenius) and Tasmanian tiger (Thylacinus cynocephalus) is "closer than people think." Researchers working on the effort claim bringing back ice age megafauna could help restore ancient ecosystems, boost carbon storage and mitigate climate change — but it remains to be seen whether it will cause catastrophic, unintended consequences.

"We have this hubris as humans that we can control our technology," Oswald Schmitz, a professor of population and community ecology at Yale University, told Live Science. "I'm not so convinced."

Animal news quiz 2024

Ants in Florida perform life-saving surgery on their peers, scientists have discovered. They are only the second animal in the world known to do this — along with humans. 

The researchers found that Florida carpenter ants (Camponotus floridanus) identify limb wounds on their nestmates, then treat them with either cleaning or amputation.

The team published its findings Tuesday (July 2) in the journal Current Biology.

"When we're talking about amputation behavior, this is literally the only case in which a sophisticated and systematic amputation of an individual by another member of its species occurs in the animal kingdom," study first author Erik Frank, a behavioral ecologist at the University of Würzburg in Germany, said in a statement.

In 2023, Frank's team discovered that an African ant species, Megaponera analis, can treat infected wounds in their nestmates with an antimicrobial substance produced in their glands. Florida carpenter ants do not have any equivalent glands, so the team wanted to find out how this species handles wounds in members of the colony. 

Specifically, the researchers looked at two types of leg wounds: lacerations on the femur (thigh) and those lower down on the tibia.

Related: 'Supergene' mutation turned ants into parasitic wannabe queens

In experiments, they observed that the ants treated their nest members' femur injuries by cleaning the wound with their mouths before amputating the leg by repeatedly biting it, while the tibia wounds were treated with just cleaning.

The surgeries resulted in significant improvements in the survival of their ant patients. Survival rates for femur injuries improved from less than 40% to between 90 and 95% when amputations were performed, while survival rates for tibia injuries improved from 15% to 75% following cleaning.

The scientists suggest ants only amputate femur injuries, rather than all leg injuries, because of speed limitations.

An amputation takes ants at least 40 minutes to complete.

After studying micro-CT scans of the ants, the researchers speculated that the damage to blood-pumping muscles in the femur causes blood circulation to slow. This would mean that bacteria-laden blood would take longer to enter the body, allowing the ants enough time to amputate the limb.

Ant tibias, meanwhile, have relatively little muscle tissue, so infections can spread faster. This means amputation would take too long for the ants to stop the spread of harmful bacteria, so they instead focus on cleaning the wound.

"The ants are able to diagnose a wound, see if it's infected or sterile, and treat it accordingly over long periods of time by other individuals — the only medical system that can rival that would be the human one," Frank said.

The ants' ability to identify and treat wounds selectively is innate, the researchers said, and that they did not find evidence of learning.

The scientists are now extending their research to other ant species that don't possess special antimicrobial glands to see if other ants have the ability to perform surgeries. 

Amazing new footage captures the moment when thousands of fire ants (Solenopsis invicta) create a life-saving raft by interlocking their limbs and mandibles.

The clip, from National Geographic's new series "A Real Bug's Life," which premieres on Disney+ on Jan 24, shows a colony of fire ants living beneath a water feature in the backyard of a home in Texas. As the water level starts to rise, the colony is seen collecting their babies and banding together before being swept over a waterfall and into a swimming pool.

Related: Watch translucent cockroach babies burst from their egg cases in skin-crawling footage

Ants are known for their collective social behavior in large colonies. When they try to swim, however, their kicking legs actively repel one another. Despite this repulsion, fire ants in groups of 10 or more are forced together by a phenomenon called the "Cheerios effect," which is caused by surface tension. This occurs when small objects, like cheerios in a bowl of milk, create a concave indentation on the liquid's surface that brings nearby objects together into clusters. 

The fire ants exploit this phenomenon to protect their queen. The larvae, pupae and worker ants are brought together, then interlock their legs and jaws to form a large raft that dips in slightly at the center. Then they place the queen on top, sitting safely in the center of this massive raft. .

The ants' nest was found while scouting backyard locations for shooting footage. Location scouts turned on a water feature in a pool, unaware that a colony of fire ants was living inside. The fire ants then flooded the pool. Bill Markham, the series producer, told Live Science that they recorded this intricate behavior with the help of Drexel University entomologist, Sean O'Donnell, using "macro lenses, split-level housings and super slow motion". Although the team did not count how many ants were part of the raft, Markham said "there were easily 5,000 on this occasion" and to their surprise, they found the ants collected trapped air bubbles to keep the raft afloat and remain buoyant. 

By smooshing together to protect their queen, they create a structure that "would take 400 times their body weight to break" said Markham. He added that these rafts can stay afloat for 12 days, but in this case they found a pool noodle and got to dry land within a few minutes.

Animals can often be unpredictable and surprise us with their unusual behavior, but some newsworthy critters take this even further, leaving scientists and the public completely baffled.

While the weird behaviors on this list are a testament to the complex brains of our furry, finned and fork-tongued friends, there's also a darker side to some of these acts. Humans continued to disrupt and destroy the natural world in 2023, putting many animals under pressure and causing some to act in weird ways. Here are 10 of the strangest animal behaviors documented in 2023.

Kangaroo tries to drown dog

In October, a man captured a video of a kangaroo as it tried to drown his dog. Mick Moloney had to rescue his dog Hutchy from the Murray River in Victoria, Australia, after a male eastern gray kangaroo (Macropus giganteus) held Hutchy's head underwater. Moloney got Hutchy to safety but took a punch from the kangaroo for his efforts.

This isn't the first time kangaroos have behaved this way around our canine companions, and the marsupial was probably just looking out for its own safety. Kangaroos have learned to hop into water to defend themselves against attacks from canines.

Crocodile has "virgin birth"

Researchers announced the first crocodile "virgin birth" in June. A female American crocodile  (Crocodylus acutus) laid a clutch of eggs at a reptile park in Costa Rica after being alone for 16 years. This form of asexual reproduction had never been documented in crocodiles before, although it's known to occur in lizards, snakes, birds and sharks.

The crocodile's clutch didn't hatch, but genetic analysis of a fetus within one of the eggs revealed it was almost identical to the mother. The study's authors noted that offspring born in this way often suffer abnormalities and don't survive.

Dolphins raid crab pots

Bottlenose dolphins were spotted stealing bait from fishers in western Australia. The dolphins used their noses and teeth to pilfer fish from nets meant for crabs. Wildlife conservationists filmed this behavior for the first time in 2023, revealing the different ways dolphins learned to open the fishers' pots.

"The most basic version is that the dolphin grabs the bait which sits on a hook or metal pin inside the crab pot," filmmaker Axel Grossmann told Live Science in November. "So essentially the dolphins pull the fish off the pin or break it down into edible pieces."

When fishers tried putting bait underneath the pots, the dolphins learned to flip them over, and when they tried using bait boxes, the dolphins learned to open them. Eventually, fishers and conservationists developed a dolphin-proof design.

Elephant peels banana

A zoo elephant taught herself to peel bananas by watching zookeepers. Pha, a female Asian elephant (Elephas maximus) at the Berlin Zoo in Germany, rips off the stem of a banana, pinches the frayed skin with her trunk and uses the fruit's weight to peel. It's an ingenious twist on the human method, which normally involves two hands and opposable thumbs.

Keepers at the zoo used to feed Pha peeled bananas when she was a calf, which is probably where she got the idea. Pha only peels ripe bananas with brown spots. She eats green and yellow bananas whole and rejects brown bananas. When fed in a group where her bananas might get stolen by other hungry elephants, she peels only her last banana, presumably to savor it.

Crocodiles save dog

Three mugger crocodiles (Crocodylus palustris) seemingly helped a young dog that had been chased into a river by a pack of feral dogs by nudging it to safety. The researchers who witnessed the event interpreted the crocodiles' actions as empathy. They also reported that the species appears to use sticks as bait to catch nesting birds and is attracted to flowers. However, an independent expert was skeptical of their findings.

"Crocodilians do have a sophisticated suite of behaviors," said Duncan Leitch, a biologist who specializes in the neurophysiology of reptiles at the University of California, Los Angeles, told Live Science in September. "But some of these conclusions are using a human definition of intelligence and trying to find that in crocodilians."

Whale kelping goes global

Researchers first documented humpback whales (Megaptera novaeangliae) playing with seaweed in 2007, but the behavior, known as "kelping," is now so widespread, it's become a global phenomenon. Seaweed potentially acts as a body scrub for the whales, and they may use it to remove parasites, treat their skin or just play with it.

"It's something they do together as a social event or by themselves," Olaf Meynecke, a researcher at Griffith University's Coastal and Marine Research Centre in Queensland, Australia, told Live Science in September. "They put the seaweed on their head and roll around in it; they try to move it around with their pectoral fins as well."

Orca eats seven sea otters whole

In September, scientists described a beached orca (Orcinus orca) with seven intact sea otters in her belly. Orcas don't normally eat sea otters (Enhydra lutris) and typically chew the marine mammals they do eat, so researchers were puzzled why this orca gobbled down the sea otters whole.

To make matters even stranger, this killer whale was found on the coast of one of the Commander Islands in the Russian Far East, far from the orcas' normal range between the Gulf of Alaska and the coast of California. One of the sea otters was stuck between the orca's oral cavity and esophagus, which could have been the reason for the orca's demise.

Ants detect cancer in urine

In January, researchers discovered that ants can sniff out cancer using their antennae. Silky ants (Formica fusca) normally use the olfactory receptors in their antennae to find food or mates, but the researchers trained them to find tumors instead.

Once the ants learned to associate the urine of tumor-bearing rodents with sugar, the researchers found that the ants spent 20% more time next to urine samples from cancerous rodents than next to urine samples from healthy rodents. The ants could serve as cheap and efficient cancer detectors in the future, though much more science needs to be done first, the researchers said. Dogs can also learn to sniff out cancer, but researchers found that ants are easier to train.

Mice kill largest flying birds

Invading mice killed eight wandering albatrosses (Diomedea exulans) — the world's largest flying birds — on a remote island between South Africa and Antarctica. The mice have been eating native seabird chicks on Marion Island for decades, but taking down adults is a new phenomenon — and it's worrying conservationists.

Humans inadvertently introduced house mice (Mus musculus) to the island in the 19th century after the rodents hitched a ride on ships. The island's native wildlife isn't equipped to defend itself against rodents because it didn't evolve alongside the mice. The Mouse-Free Marion project will try to use rodenticide to kill off the mice before they can do any further harm to wandering albatrosses and other threatened species that call the island home.

Orcas sink two boats

Orcas in the Strait of Gibraltar sank two boats in 2023 and attacked a number of others with ruthless efficiency. Why orcas have started attacking boats is an open question, but the behavior may stem from a traumatic experience, play, frustration or a temporary fad within the population. 

In the 1980s, an orca population in the Pacific went through a phase of carrying dead salmon on their heads for no obvious reason, so it's possible for orcas to pick up temporary behaviors and teach them to each other. The coordinated boat attacks are just one example of how orcas show their terrifying intelligence.

Ants' complex caste system may be partly controlled by the insect version of the blood-brain barrier, a gatekeeper that only lets certain substances into the brain, a new study reveals.

An anthill is a meticulously organized community of insects, with clear divisions of labor to ensure smooth operation. While the queen lays eggs, worker ants either forage for food or protect the nest as soldiers, and the ants' hormones, including one called "juvenile hormone," dictate which role each ant plays.

However, the underlying molecular controls that regulate these hormones to shape social behavior have not been well understood.

Now, a recent study has shown that the blood-brain barrier (BBB), the filter that protects the brain from unneeded or potentially harmful substances, plays a role in this process. The findings, published Sept. 7 in the journal Cell, indicate that the ant BBB regulates hormone levels entering the brain, thus influencing worker ants' roles in the colony.

Related: These ant queens live 500% longer than workers. Now we know why.

In the study, researchers set out to understand the basis of the behavioral differences between forager and soldier ants. They investigated which genes and proteins were expressed differently among these two classes of worker Florida carpenter ants (Camponotus floridanus). They discovered that an enzyme that breaks down juvenile hormone, called juvenile hormone esterase, was present only in the cells that make up the ants' BBBs.

Their analysis revealed that soldier ants had higher levels of juvenile hormone esterase than foragers did, and therefore, less of the hormone was making it into the soldiers' brains.

When the researchers injected juvenile hormone directly into the brains of soldier ants, bypassing the BBB, the ants abandoned their mercenary role and started looking for food. The ants showed a similar shift in social behavior when the researchers reduced their supply of juvenile hormone esterase by manipulating the gene that produces it. Without an enzyme to break it down, juvenile hormone reached the ants' brains and reprogramed their behavior.

Previous studies had reported that the BBB may regulate the hormone levels in the insects' brains, study co-first author Karl Glastad, a researcher at the University of Pennsylvania, told Live Science in an email.

"However, the fact that the ant blood-brain barrier was dynamically regulating juvenile hormone between these two worker types in a way that controlled such an important behavior was definitely surprising to us," he said.

"That the access of juvenile hormone to the brain is regulated so tightly at the level of the blood-brain barrier is a really cool finding," Daniel Kronauer, an evolutionary biologist at The Rockefeller University who was not involved in the study, told Live Science in an email.

To see whether the enzyme would affect a less socially complex insect, the research team conducted experiments in fruit flies (Drosophila melanogaster). Switching on the gene for juvenile hormone esterase in the fly BBB triggered behavioral changes similar to those seen in ants: The genetically modified flies spent less time looking for food than their unmodified peers did.

Understanding what factors control the amount of juvenile hormone esterase that ends up in an ant's BBB requires more work, Glastad said. But these findings do highlight an unappreciated role of the BBB in insects. It is more than a passive sieve — it is an active component of an entire behavioral circuit, he said.

To explore whether other animals use similar mechanisms to control which hormones enter the brain, the researchers analyzed published data from other labs. They found that some hormone-degrading enzymes are also present in cells of the mouse BBB. (Similar enzymes have not been found in the human BBB, but the structure controls hormones in other ways.)

"It would be extremely surprising to me if other similar independently-evolved mechanisms do not exist in other organisms," Glastad said.

Although Kronauer said he was cautious about extending the findings from insects to mammals, he acknowledged the possibility that the BBB in mammals may have similar systems that regulate hormone levels in the brain by breaking the molecules down.

"But that will require more experimental work to figure out," he said.

Ants that inflict the world's most painful stings do so by injecting venom that targets their victim's nerve cells, new research has found.

Australian greenhead ants (Rhytidoponera metallica) and bullet ants (Paraponera clavata), found in Central and South America, are not to be messed with. These insects' stings unleash a flood of toxins that cause trembling, uncontrollable and long-lasting pain in humans and other mammals.

In his 2016 book "The Sting of the Wild" (Johns Hopkins University Press), entomologist Justin O. Schmidt described being stung by a bullet ant as "pure, intense, brilliant pain. Like walking over flaming charcoal with a three-inch [8 centimeters] nail embedded in your heel."

Victims of these ants have also likened the pain to that of being shot, giving the insect its name.

"Bullet ant stings can be painful for up to 12 hours and it's a deep drilling pain you feel in your bones with sweating and goosebumps," Sam Robinson, a biopharmacologist at the University of Queensland's Institute for Molecular Bioscience who led the new research, said in a statement.

Related: Killer bees stung a man 250 times in swarm attack, but he survived. How?

Now, Robinson and his colleagues think they know how these ants pack such vicious stings.

In a study published May 23 in the journal Nature Communications, the scientists showed that the ant venom targets specific proteins in nerve cells that are involved in pain perception.

Greenhead and bullet ants produce toxins that bind to mammalian nerve cells when they sting. Researchers already knew bullet ants produce a substance targeting nerves called poneratoxin, but it remained unclear how this substance produced such intense and long-lasting pain.

To find out, the team investigated the toxin's effect on proteins embedded in the membrane of nerve cells called voltage-gated sodium channels, which serve a critical role in pain signaling. 

These channels regulate how much sodium enters and exits cells, which determines the length and strength of pain signals, supporting neurological and muscle function in animals. Many venomous animals have evolved toxins that target sodium channels, including some scorpions, such as the yellow fat-tailed scorpion (Androctonus australis). 

The researchers found that the venoms of greenhead and bullet ants, as well as another species called Tetramorium africanum, also target sodium channels. The ants' toxins unlock these channels and prevent them from shutting again, prolonging and intensifying the pain signal.

"We discovered that the ant toxins bind to the sodium channels and cause them to open more easily and stay open and active, which translates to a long-lasting pain signal," Robinson said in the statement.

While this mechanism could explain the excruciating pain caused by the ants' stings, there may be other factors at play that are yet to be discovered, the authors wrote in the study.

The findings could shed light on the molecular underpinnings of pain perception and pave the way for new treatments for pain. "We want to understand pain at a molecular level and toxins are fantastic tools to do this," Robinson said.

About a decade ago, scientists observing clonal raider ants spotted something strange: Although the species is known to be queenless, a few ants were posing as queens of the colony, lording over their hardworking counterparts. These wannabe queens had wing stubs, as well as giant eyes and ovaries.

Researchers had long assumed that these "workerless social parasite" ants, which depend on other workers for survival, acquired these traits one by one, through a series of mutations. But now, scientists have discovered that a single mutation of a "supergene" can turn regular clonal raider ants (Ooceraea biroi) workers into lazy queenlike parasites.

"This was a shocking discovery," Waring "Buck" Trible, an entomologist, John Harvard Distinguished Science Fellow and the lead author of the study in which the findings were published, told Live Science in an email. "The clonal raider ant is a queenless ant species, and no winged female adults have been observed in this species previously." 

The pseudo queens are born with wings that they shed as adults, but they retain visible scars. They are the same size as worker ants, but their general indifference to labor such as brood care, foraging and nest defense makes them stand out in the colony.

Related: Mutant 'daddy shortlegs' created in a lab 

The researchers isolated the parasites and found that their offspring also had wings, suggesting that the queenlike traits were genetic. They ran analyses to confirm this observation and discovered a mutation in a "supergene" on chromosome 13.

This single mutation may be the switch that turned clonal raider ants from the "wild type" usually found in nature into a mutant variant of the same species.

"That's actually really surprising, given that the parasites differ from the wild types in so many traits, including morphology [a segmented thorax], anatomy, and even behavior," Daniel Kronauer, an associate professor and head of the Laboratory of Social Evolution and Behavior at The Rockefeller University in New York City, told Live Science in an email. 

"What we describe here is a mutant strain that is extremely closely related to its wild type ancestors. So it's not really a different species, but maybe what could be considered an intermediate form," Kronauer added.

The researchers noted that the wannabe queens laid twice as many eggs as regular clonal raider ants. They can't let their numbers grow too big, however, because they need the workers. "When they become too common they run into problems," Kronauer said. The parasites catch their bulky wings on their pupal skin when molting, and if there aren't enough workers around to help untangle them, many of them die.

The sweet spot seems to be when the parasites make up around a quarter of the colony, according to the study, published Feb. 28 in the journal Current Biology. When the wannabe queens' proportion was higher, their survival rates plummeted. 

While some species of exclusively social parasite ant queens exist in the wild, the clonal raider ant is the first documented to have evolved wannabes within its own species.

"I was very surprised to find these ants," Kronauer said. "Social parasites are typically very rare, and can only be found in a few colonies of the host species. But the crazy thing in this case is that the parasites must have arisen within the host colony via a mutation, rather than having infiltrated the colony from outside, which is the case with social parasites in the wild."

Ants can be trained to detect cancer in urine, a new study finds.

Although ant sniffing is a long way from being used as a diagnostic tool in humans, the results are encouraging, the researchers said.

Because ants lack noses, they use olfactory receptors on their antennae to help them find food or sniff out potential mates. For the study, published Jan. 25 in the journal Proceedings of the Royal Society B: Biological Sciences, scientists trained nearly three dozen silky ants (Formica fusca) to use these acute olfactory receptors for a different task: finding tumors.

In a lab, scientists grafted slices of breast cancer tumors from human samples onto mice and taught the 35 insects to "associate urine from the tumor-bearing rodents with sugar," according to The Washington Post. Once placed in a petri dish, the ants spent 20% more time next to urine samples containing cancerous tumors versus healthy urine, according to the study.

"They just want to eat sugar," Baptiste Piqueret, the study's lead author and an ethologist at Sorbonne Paris North University in France, told The Washington Post.

Related: Some cancer cells grow stronger after chemo. Research hints at how to kill them.

Because tumor cells contain volatile organic compounds (VOCs) that researchers can use as cancer biomarkers, animals such as dogs — and now ants — can be quickly trained to detect these anomalies through their sense of smell. However, researchers think that ants "may have the edge over dogs and other animals that are [more] time-consuming to train," according to The Washington Post. 

This is important because the earlier cancer is detected, the sooner treatment can begin. The researchers are hopeful that cancer-sniffing ants have the potential "to act as efficient and inexpensive cancer bio-detectors," they wrote in their study. 

"The results are very promising," Piqueret said. However, he cautioned that "it's important to know that we are far from using them as a daily way to detect cancer."

Creepy-crawlies with a menacing bite that can trigger an insatiable itch, ants are the stuff of nightmares for many people. A close-up image of one of these pint-size terrors from Nikon's Small World Photomicrography Competition 2022 is eliciting a horrified response that has spread across the internet like venom through the lymphatic system. 

Eugenijus Kavaliauskas, a Lithuanian photographer, captured the horrific sight, which earned him an "Images of Distinction" nod from the judges. Appropriately titled "Ant (Camponotus)," the image was captured by magnifying the ant's alien-like face five times under a stereo 10x microscope. Kavaliauskas called it an example of "God's designs and the many interesting, beautiful, unknown miracles under people's feet," according to The Washington Post.

So, what makes this zoomed-in image so frightening? Perhaps it's the insect's antennae, which look eerily similar to a demon's piercing red eyes. Or maybe it's the insect's razor-sharp teeth built to pierce its victim's flesh with a single bite.

Related: Trap-jaw ants' lightning-fast bite should rip their heads apart. Here's why it doesn't.

The creepy image isn't the only scary thing about ants. Entomologists have documented ants morphing into zombies after coming into contact with mind-controlling parasites, vomiting into each other’s mouths to form social bonds and queens willingly sacrificing themselves as a way to retain the throne.

The ant image wasn't the only one that caught the judges' attention. Other spooky snaps that earned awards included a tiger beetle devouring a fly, a hulking blob of slime and a psychedelic image of a stained dinosaur bone.

How far would you go to increase your life span by 500%? One ant species engages in brutal colony-wide brawls to replace recently deceased queens — and the victor not only gains the throne, but also gets a dramatic boost to their longevity.

Upon the death of a queen, Indian jumping ants (Harpegnathos saltator) battle to see which worker will take the queen's place. Winning the crown means more than pumping out eggs — it also means living 500% longer than the average worker. Now, scientists may have pinpointed how substitute queens slow their aging. 

The secret lies in a protein called Imp-L2, which counteracts some of the effects of insulin in the substitute queen ant's body, according to a new study, published Thursday (Sept. 1) in the journal Science.  

In general, the hormone insulin helps direct sugar from the circulatory system into cells, where it can be used for fuel. The substitute queens — officially known as pseudoqueens or gamergates, in reference to the Greek words for "married worker" not the misogynist online harassment campaign GamerGate — must boost their production of insulin to contend with the incredible amount of food they must consume. "If you want to make eggs, you need to have a lot of insulin because you eat constantly," co-senior author Claude Desplan, a professor of biology and neural science at New York University, told Live Science. 

Related: These vegetarian ants have steak knives for teeth, new study finds 

Although necessary, this influx of insulin should theoretically come with a catch: In addition to helping shuttle sugar into cells, insulin sets off several molecular chain reactions, some of which contribute to the aging process. Specifically, the "Akt signaling pathway" — which is involved in many cellular functions, ranging from metabolism to cell survival — can be activated by insulin and has long been tied to aging and age-related disease.

So, if a pseudoqueen starts pumping out huge quantities of insulin, in theory she should age more quickly than the average worker ant, who doesn't make as much of the hormone. "However, in the case of these ants, it's the exact opposite," Desplan said. The median life span of a typical worker ant is nearly eight months, while pseudoqueens can live for about three years and three months. "It's a huge extension of the life span," he said.

And interestingly, if a pseudoqueen is placed in a different colony with an already-established ruler, she'll revert to being a normal worker, Desplan said. These former pseudoqueens are called "revertants" and have life spans similar to those of workers. Somehow, only queens and pseudoqueens, despite all their insulin, manage to survive for years on end.

To solve this apparent paradox, Desplan teamed up with his longtime collaborator Danny Reinberg, a professor of biochemistry and molecular pharmacology at the NYU Grossman School of Medicine. 

Their team sampled tissues from H. saltator workers, revertants and pseudoqueens, focusing on tissues involved in metabolism and reproduction. These included the brain, ovaries, fat body, an organ similar to the human liver and adipose (fat). Using a technique called bulk RNA sequencing, the team analyzed which proteins were being built in the sampled tissues. A molecular cousin of DNA, RNA carries genetic instructions on how to build proteins, ferrying these blueprints from the cell's command center to one of the cell's protein construction sites. 

By peeking at these RNA instructions, the team discovered that, compared with workers and revertants, pseudoqueens produced much more insulin in the brain and began producing more fat and vitellogenin — a precursor to egg yolk — in the fat body. Some of these resources from the fat body was transported to the ovaries, to support egg production, and some of the fat went into making a unique pheromone that only queens and pseudoqueens exude. (It's the disappearance of this pheromone in a nest that prompts worker ants to duel after their queen dies.)

Related: Trap-jaw ants' lightning-fast bite should rip their heads apart. Here's why it doesn't.

As pseudoqueens make more insulin, their ovaries grow and develop so that they can carry eggs. The insulin directs this ovary maturation process through the "MAPK signaling pathway," another chain of chemical reactions that can be set off by insulin. At the same time, the ovaries make Imp-L2, the team discovered, which essentially blocks the Akt signaling pathway that could otherwise cause rapid aging in the pseudoqueen. 

Imp-L2 secreted from the ovaries also makes its way to the fat body and provides an anti-aging shield to that organ, too, the team determined.

"The two main branches of the insulin signaling pathway" — MAPK and Akt — "appear to differentially regulate fertility and lifespan, with increased signaling in one aiding reproduction in pseudoqueens and decreased signaling in the other consistent with their extended longevity," Reinberg said in a statement. 

The team's next step will be to understand how Imp-L2 blocks only the aging-related pathway and not the reproduction-related one, Desplan told Live Science. They plan to study the effects of the insulin-blocking protein in additional insects, including fruit flies, and then eventually in mammals. 

"We don't know exactly what's going to happen," Desplan said. "Flies and ants aren't exactly similar to one another." And it's even more difficult to predict whether the anti-aging benefits Imp-L2 grants to Indian jumping ants would carry over to noninsects, such as mammals, he said.

Originally published on Live Science. 

In early 2020, ornithologist Noah Strycker found himself walking amongst several thousand chinstrap penguins on Elephant Island, a remote blip of snow-covered rock just off the Antarctic Peninsula. He was there to carry out a census of the island's penguin colony, which hadn't been properly surveyed since 1970. "I'll never forget the sight, sound, and...smell," joked Strycker, a graduate student at Stony Brook University in New York, as well as a professional bird watcher, and author.

The survey that he and his colleagues eventually produced revealed that chinstrap penguin numbers are in decline. But despite this, this species actually forms one of the biggest colonies of penguins on Earth — gathering in the millions in some Antarctic locations. But counting these animals doesn't daunt Strycker, who has actually developed something of a hobby for this task. 

It started a few years ago when he found himself pondering how many starlings were contained in the magical murmurations that these birds form, and which swell and undulate across the evening sky in many parts of the world. "They are quite beautiful. It almost looks like smoke," Strycker told Live Science. "And it just gets you wondering, how many of them are there?" The answer, he discovered, was that there are roughly 1 million in the average murmuration, all soaring and swooping in unison. That discovery spurred Strycker on to answer an even more ambitious question: beyond birds, what's the biggest group of animals ever recorded on Earth?

Related: What's the first species humans drove to extinction?

Answering this question takes us to some very interesting places — back into the past, up into the sky, down into the ocean and sweeping across desert plains. It offers magnificent proof of the abundance of animal life on Earth, but it also points to humanity's role in reducing — and, unexpectedly, increasing it too.

Thousands, millions, billions

When Strycker embarked upon his unusual quest, he shared his discoveries in his book called "The Thing with Feathers: The Surprising Lives of Birds and What They Reveal About Being Human" (Penguin Random House, 2014). As the title suggests, birds are high contenders for the title of most numerous group. At 1 million per flock, starling numbers are jaw-droppingly high — but they're easily outnumbered by chinstrap penguins, which can reach 2 million on the South Sandwich Islands off Antarctica. 

But those charismatic penguins fall far behind the red-billed quelea: this small species that can gather in single flocks of several million over savannah and grassland areas in sub-Saharan Africa — so huge that they seem to roar as they pass overhead. "I think they're considered now to be the most abundant species of bird in the world. And they do make very large flocks in the millions — tens of millions, maybe hundreds of millions," Strycker said. Their explosive success as a species may be helped by agriculture's spread: these birds consume grass seeds, but they'll also settle for fields of cultivated grain. As such, they're loathed by embattled farmers who lose huge shares of barley, buckwheat and sorghum harvests to these birds every year.

Quelea are so numerous that observers say it can take five hours for a flock to pass overhead. But here is where this species yields to an even more populous bird that once was abundant across American skies: the passenger pigeon. "There are stories of people standing there and watching a single flock of passenger pigeons fly over them for hours or days at a time, which is crazy!" Strycker said. One gathering in 1866 was recorded as 1 mile (1.6 kilometers) wide and 300 miles (482 km) long, and was estimated to contain about 3.5 billion birds, based on the number of pigeons per square mile and extrapolated across the size of the flock. Of course, that was before hunting drove this successful species to extinction. 

So surely with that grand tally, this pigeon of yore takes the prize for most populous creature on Earth? Not so fast: there are quite a few other contenders to consider still. 

Related: Why are there so many pigeons?

Shifting our gaze down from the skies, and into the ocean's depths, there are records of fish species — specifically Atlantic herring — gathering in schools that exceed 4 billion — the passenger pigeon's closest contender for the reigning title so far. Other species don't come close to the numbers tallied up so far — but they're still so impressive to behold that they deserve a mention. These include migratory mammals like springbok and wildebeest in southern Africa that have, in the past, gathered in herds exceeding 1 million, forming vast processionals that march across the sun-beaten savanna for weeks. These are further outstripped by their winged mammalian cousins: in Texas, there's a single cave that's home to more than 20 million Mexican free-tailed bats, whose closely-packed bodies transform the cave's interior into a rippling, writhing mass.

Yet there's one animal whose enormous gatherings leave all these other contenders behind in a trail of dust. (Or rather, a trail of decimated vegetation and ravaged crops.)

A gathering swarm

In East Africa earlier this year, a veil of insects swept across the sky, forming a mass of spiky legs and fluttering wings that spanned nearly 930 square miles (2,400 square km). "It was literally like a black blanket that went over the clouds. It was difficult to even see the clouds," said Emily Kimathi, a researcher at the International Center of Insect Physiology and Ecology in Kenya. 

That swarm was composed of desert locusts, a species that turns up in huge numbers sporadically in East and North Africa, as well as parts of the Middle East and South Asia. That particular event was the largest swarm seen in the Horn of Africa in 25 years. Experts estimate that locusts swarm at a density of about 50 million per 0.3 square miles (1 square km), so that means the single 2020 throng would have contained roughly 200 billion locusts, said Kimathi, who studies the desert locust. "[The species] can increase up to 20 times its population in a span of three months." 

What Kimathi is concerned about is how much more frequent — and larger — these swarms could become. The desert locust needs two things to thrive: heat, and moisture, which is crucial for the eggs to hatch from the desert sands. And fortuitously for locusts, climate change is increasing these conditions across their vast range. "These areas are getting more arid, and when they do receive the rainfall, it's torrential rain," Kimathi said. "These conditions are becoming more frequent. And so these areas are becoming more favorable for locusts to breed."

Related: What makes grasshoppers swarm?

In this case, the gathering of gregarious animals isn't just a spectacle to behold; a voracious swarm of locusts can decimate farmers' crops in a matter of hours, ruining livelihoods and increasing food insecurity for millions. 

Kimathi is trying to tackle this enormous challenge in her research. In a recent study published in July in the journal Scientific Reports, she used meteorological data, paired with information on the breeding patterns of desert locusts, to develop models that identify precise geographical locations across the region where species are most likely to breed in the future. She's hoping her findings will inform early-warning systems that countries can use to predict where locusts will breed, so they can be intercepted before eggs hatch and take to the skies in ever-growing swarms. 

Two-hundred billion is an eye-popping number. But a clue from history suggests that locust swarms can grow much more numerous, given the perfect conditions. In 1875, an amateur meteorologist named Albert Child stood, bewitched, as locusts whizzed across the sky in a swarm that ultimately cloaked a large portion of the western United States. The species was the Rocky Mountain locust, and Child estimated the swarm covered an area of 198,000 square miles (512,800 square km). 

This historical event became known as 'Albert's Swarm', and based on Child’s estimates, it was thought to contain not millions, not billions, but trillions of insects. Three-and-a-half trillion, to be exact. And that, in fact, is thought to be the largest number of animals in a group ever recorded by a human. Rocky Mountain locusts have since gone extinct — but their historic flight offers us a cautionary look at those other swarms, gathering across the planet today.

Will we ever know?

It's overwhelming to contemplate what several trillion locusts looks like. But, take a breath, because there's one final contender on our list — if we go with a slightly more liberal definition of what a 'group' entails. That's because beneath the Earth's surface, we find creatures that gather in colonies so vast, it's almost inconceivable that they form a unit. 

This is the Argentine ant, which was unintentionally introduced from South America to Europe about 100 years ago. This industrious creature has formed the world's largest known continuous colony: a behemoth that stretches 3,700 miles (6,000 km) underground across vast swathes of Europe. The stretch is made up of several hundred nests that each contain billions of ants — so it's likely that the whole system collectively contains trillions. But getting to a closer estimate has proven elusive: the task of counting these insects may simply be too challenging.

This underscores the difficulty of answering this deceptively simple question, of what animal forms the biggest group. "It seems like such a quantifiable question, and yet the more you dig down into it, the harder it becomes to define what do you mean by a 'group'. It's so difficult to estimate large concentrations," Strycker said. And what's more, as the case of the locusts reveals, "The more you dive into it, the more you can't answer that question without talking about ourselves," he said. The boom and bust of animal populations isn’t something we can separate from human influence. 

Maybe the important thing is that contemplating the sheer abundance of life on Earth — and the roles humans play in making it fall, and rise — will help us do a better job of protecting it. 

Editor's Note: This piece was updated Dec. 23 to clarify that chinstrap penguins form one of the largest penguin colonies on Earth, but not, in fact, the largest.

Originally published on Live Science Dec. 19, 2020, and republished on July 28, 2022.

Moving at speeds thousands of times faster than the blink of an eye, the spring-loaded jaws of a trap-jaw ant catch the insect's prey by surprise and can also launch the ant into the air if it aims its chompers at the ground. Now, scientists have revealed how the ant's jaws can snap closed at blistering speeds without shattering from the force.  

In a new study, published Thursday (July 21) in the Journal of Experimental Biology, a team of biologists and engineers studied a species of trap-jaw ant called Odontomachus brunneus, native to parts of the U.S., Central America and the West Indies. To build up power for their lightning-fast bites, the ants first stretch their jaws apart, so they form a 180 degree angle, and "cock" them against latches inside their heads. Enormous muscles, attached to each jaw by a tendon-like cord, pull the jaws into place and then flex to build up a store of elastic energy; this flexion is so extreme that it warps the sides of the ant's head, causing them to bow inward, the team found. When the ant strikes, its jaws unlatch and that stored energy gets released at once, sending the jaws smashing together.      

The researchers examined this spring-loaded mechanism in fine detail, but the project's engineers puzzled over how the system could work without generating too much friction. Friction would not only slow the jaws down, but would also generate destructive wear-and-tear at each jaw's point of rotation. Using mathematical modeling, they eventually found an answer as to how trap-jaw ants avoid this problem.

"This is the part that engineers are incredibly excited about," in part because the discovery could pave the way for the construction of tiny robots whose parts can rotate with unparalleled speed and precision, Sheila Patek, the Hehmeyer Professor of Biology at Duke University in Durham, North Carolina, and the study's senior author, told Live Science.

Related: What do ants smell like? 

A nearly-frictionless, spring-loaded system 

To study the incredible jaws of O. brunneus, Patek and her colleagues collected ants from a colony found in the scrubland near Lake Placid, Florida. Back in the lab, the team dissected some of the ants and took detailed measurements and micro-CT scans of their body parts, particularly their jaws and the muscles and exoskeleton of the head. They later plugged these measurements into their mathematical models of the ants' movements. 

In addition, the team placed some ants in front of a high-speed camera that captured footage at a whopping 300,000 frames per second. (Video is typically filmed at 24 to 30 frames per second, for comparison.) These videos revealed that, as the ants prepared to strike, the exoskeleton covering their heads underwent significant compression, shortening by about 3%, length-wise, and growing about 6% skinnier around the middle. This compression took place over several seconds, which feels slow compared with the ant's speedy bite, Patek said.

Once released from their latches, the ants' jaws swung through a perfect arc, reaching their peak velocity around the 65 degree mark before beginning to decelerate. At their fastest, the tips of the ants' jaws traveled roughly 120 mph (195 km/h) through the air.

This ultrafast motion unfolded smoothly and precisely thanks to several forces acting on the jaws at the same time, the team determined. 

For one, as the ant's head popped back into its normal shape, it catapulted the tip of each jaw out into space. Meanwhile, the large muscles inside the ant's head relaxed and stopped stretching out the tendon-like cords to which they were attached. As each cord settled back to its normal length — think of a stretched-out rubber band suddenly being released — it yanked on the end of the jaw that sits inside the ant's head. It's this simultaneous pushing and pulling that sent the ant's jaws flying towards one another.

Related: These worker ants drag their queens to far-off bachelor pads to mate 

A similar principle applies when you spin a bottle on a flat surface; the twisting motion required to spin the bottle involves pushing one end of the bottle forward while pulling the other end backwards. Likewise, when ballerinas perform pirouettes with the support of a partner, the partner will push one of her hips forward and pull the other back to set her turn in motion. However, the best analogy for the trap jaw ant's mandible motion might be stick juggling, a circus art in which performers use two sticks to twirl a baton in mid-air.

The baton encounters little friction as it flips through the air, and based on their mathematical models, the study authors think that a trap-jaw ant's mandibles are similarly unconstrained. At first, the researchers thought that each jaw might pivot around a pin joint, similar to a door on a hinge, but they determined that such a structure would introduce too much resistance. Instead, they found that the jaws rotate around a far less rigid joint structure that requires little reinforcement in the ant's head.

"The dual spring mechanism drastically reduces reaction forces and friction at this joint so that the joint does not need very much reinforcement in order to hold the mandible in place," study co-first author Gregory Sutton, a Royal Society University Research Fellow at the University of Lincoln in England, told Live Science in an email. The lack of friction in this system may explain how trap-jaw ants can strike again and again without ever injuring themselves, the authors concluded.

The authors think that all trap-jaw ants in the Odontomachus genus use the same spring-loaded mechanism to bite, but trap-jaw ants in other genera may use a slightly different strategy, Patek said. That said, Patek suspects that the mechanism they discovered may well be used by other arthropods, meaning insects, spiders and crustaceans. 

For example, mantis shrimp, famous for throwing 50 mph (80 km/h) punches, likely warp their exoskeletons and use super-stretchy tendons to build up power for each strike — although such a mechanism has not yet been identified in the shrimp.   

"We're starting to realize that this is going to be the rule of thumb for these super-fast arthropods," Patek said.

Originally published on Live Science.

The days of invasive crazy ants — whose supercolonies can support millions upon millions of the fierce insects — may be numbered. That's because a deadly fungus that uses spring-loaded harpoonlike barbs to pierce the ants' gut cells is wiping out their colonies across the Southeastern United States.  

That's not a bad thing. Tawny crazy ants (Nylanderia fulva), which are originally from South America, have over the past two decades become an increasingly problematic pest species and a threat to local wildlife in the U.S., by creating vast supercolonies. 

Scientists with the University of Texas at Austin's (UTA) Brackenridge Field Laboratory recently identified a type of fungus that seemingly only targets tawny crazy ants, sparing native ant species and other arthropods. One ant colony infected with the fungus can spread the pathogen to others that are nearby, leading to the collapse of a supercolony and triggering the extinction of a crazy ant population within just a few years, the researchers reported in a new study.

In South America, tawny crazy ant nests are self-contained and the insects will battle ferociously with neighboring crazy ant colonies. But North America's invasive crazy ants follow a different strategy, in which new nests emerge out of an existing one — a process known as budding — and all the colonies' ants in a given area recognize each other as close relatives and move freely between nests, said Edward LeBrun, lead author of the new study and a research scientist in UTA's Department of Integrative Biology.

These nests "spread like bacterial plaque across a landscape," LeBrun told Live Science. "Every meter there's a nest, and that's over many square kilometers. How many ants are there? Many, many, many millions," LeBrun said.

Related: Murder hornets and monkey cannibals: 10 times nature freaked us out

Because crazy ants multiply quickly, they can swiftly become so numerous that they overwhelm local insects, arthropods, and small mammals and reptiles. They also swarm in human homes, multiplying by the thousands in basements, crawlspaces and walls, and even inside electronics, Live Science previously reported. But while forming supercolonies may have previously benefited crazy ants, living in a network of linked nests could prove to be their downfall by aiding the spread of a lethal pathogen, scientists reported March 28 in the journal Proceedings of the National Academy of Sciences.

In 2015, LeBrun and his colleagues described a previously unknown microsporidian — a type of fungus — in tawny crazy ants that had been sent from Florida to their Texas laboratory. The ants had enlarged abdomens that were stuffed with white, fatty tissue, which happens when a microsporidia infection turns an ant into a spore factory, LeBrun explained. When the researchers checked Gulf Coast tawny crazy ant colonies, they found the fungus in local ants, too; they named the pathogen Myrmecomorba nylanderiae, taking the species name from the host ant.

M. nylanderiae spores are cylindrical capsules containing a tightly coiled filament tipped with a harpoonlike barb at one end. After a spore is swallowed by an ant, a chemical trigger in the insect's gut signals the spore to release the projectile within. 

"If it happens to be close to the gut epithelium [a thin type of animal tissue], it'll puncture the cell wall of its host and then it injects the entire contents of the spore cell into the host cell," LeBrun said. The spore then hijacks the host cell's machinery to replicate itself, creating more spores and jumping into more cells, much as a virus replicates in a host, he explained. 

Inoculating an infestation

For nine years, the researchers observed and sampled 15 infected and uninfected crazy ant colonies, discovering that all of the infected populations declined over time, and more than 60% of them disappeared completely within four to seven years of acquiring the pathogen. The scientists then tested the effects of the fungus by sending infected ants into uninfected crazy ant nests in Estero Llano Grande State Park in Weslaco, Texas. Within two years after introducing the pathogen, the park's previously "apocalyptic" crazy ant infestation had dwindled away into nothing.

The fungus did its lethal work by shortening the life spans of infected workers by about 23%, slashing a colony's workforce, LeBrun said. Workers would also transmit the infection to developing larvae, reducing the number of young that would develop into workers and ensuring that the next generation of workers would also be short-lived. Tawny crazy ant queens take a break from laying eggs during the winter, and don't resume egg laying until spring; in infected colonies, with every new egg-producing season there would be fewer new workers to care for the brood after the older workers died off. Over time, this would guarantee the colony's decline and eventual demise, according to the study.

Scientists don't yet know where the fungus came from — if it originated with crazy ants in South America, or if the ants first encountered it in the U.S. — but it doesn't seem to affect arthropods that are native to the Gulf Coast. This means that the fungus could be used to eradicate invading crazy ants and enable local species to safely return to the ecosystems where they once lived. But because the process of inoculating and tracking infection in a crazy ant colony is labor-intensive and technically challenging, it may be some time before this method is available as an off-the-shelf crazy ant solution for homeowners, Lebrun told Live Science.

"Its application is most likely going to be around areas of high conservation value or where there are endangered species, like state parks or national parks," he said.

Originally published on Live Science.

Every queen needs a crown. For the queen ant Monomorium triviale, that crown bursts and bubbles out of her head, back and abdomen while she's still a larva — leaving worker ants little confusion about who's the boss, even when the boss is a baby.

M. triviale are amber-colored ants native to China, Japan and South Korea. The queen ants of the species can produce offspring by laying unfertilized eggs — no males necessary — in a process called thelytokous parthenogenesis. In fact, a new study published March 3 in the journal Zootaxa points out, no male M. triviale have ever been identified; all known M. triviale ants fit into two categories: sterile female workers and fertile queens. 

In their new study, researchers wanted to better understand the differences between these two ant classes, starting at the earliest larval stages. The team collected some M. triviale nests from a thicket in the suburbs of Kyoto, Japan, then transferred the immature colony members to artificial nests in a laboratory. There, the researchers studied the ant larvae using several types of high-definition microscopy.

As the worker and queen ants developed, they periodically shed their exoskeletons, taking on strange new forms (or "instars") with every molting. Both queens and workers started as oblong blobs, before developing mouthparts and tiny, spiky hairs along their bodies within a few days of hatching, the researchers wrote. 

Related: What do ants smell like?

As the worker and queen ants developed, they periodically shed their exoskeletons, taking on strange new forms (or "instars") with every molting. Both queens and workers started as oblong blobs, before developing mouthparts and tiny, spiky hairs along their bodies within a few days of hatching, the researchers wrote. 

But in her final larval form, the queen ant pulled off a look unlike any other. Her body had gone almost completely hairless, the team found, and had instead sprouted 37 doorknob-like lumps, or "tubercles" all along its length, giving her a look something like an alien plushie doll, or a Panic Pete squeeze toy from a parallel universe.

When the researchers probed the interior of these tubercles, they found that the lumps were made of extended skin and cuticle, and they were about twice as thick as any other part of the queen's body. The lumps contained no muscle, ducts or specialized parts, raising the question: What are the ant queen's fleshy lumps actually good for?

The study authors couldn't say for sure, but they pointed to five possible explanations from a 1976 paper whose authors had looked at the morphology of various ant larvae. The structures could help support the larvae's bodies, allow them to cling to nest ceilings or walls, or they might help queens defend against cannibal attacks from other larvae, the researchers wrote.

Alternatively, the lumps could be involved in feeding, possibly being used to hold food to the larva's body surface, or to help pass food between larvae.

"The function of queen-specific tubercles of the M. triviale larvae is still unclear at this time," the authors of the new study wrote in the paper. "Behavioral observations of the interaction between the workers and the queen larvae… will help us understand the hidden but essential roles larvae play in complex ant societies."

It's a lot of look, but M. triviale's larva queens pull it off. Now, scientists just need to figure out why. 

Originally published on Live Science.

Skunks are notoriously stinky. The musk ox, true to its name, emits a musky scent during mating season. And for some lucky owners, dog paws smell like corn chips. But these are not the only members of the animal kingdom that are smelly. Perhaps one of the most peculiar stinky animals is right under your nose: ants.

Most people have come across ants in their lives. So why don't most people know that ants smell?

There are more than 13,000 ant species. When Clint Penick, an assistant professor of ecology, evolution and organismal biology at Kennesaw State University in Georgia, tells people that he studies these critters, he often gets this question: "Red ants or black ants?" But there are more useful and creative ways to distinguish ant species, Penick told Live Science. One of them is by smell.

Related: Why are some smells so hard to get rid of?

"If I find a species I'm familiar with, I might pick it up and crush it," he said. "The smell can sometimes help me narrow down which group of ants it might be from."

Not all ant species are odorous enough for the human nose to detect their scent. Of those that are, the scent may be mild, and some can be smelled only after being crushed, Penick said. However, some ants can be smelled from a distance if they're in a large enough colony.

There are four main smells that ants are known to emit. The first is citronella — from the aptly named citronella ants, also known as larger yellow ants (Lasius interjectus) and smaller yellow ants (Lasius claviger) — although some people describe these ants' odor as lemon. "The citronella smell is thought to be something that they use to defend themselves or make them distasteful to predators," Penick said.

The smell of trap-jaw ants (Odontomachus) is anything but distasteful — it smells like chocolate. These predator ants produce an alarm pheromone in a gland in their head to let other members of the colony know when they're in danger, and it emits a chocolate-like aroma. Sadly, these ants have to be crushed to be smelled. "I've done it only once to see if it was true but normally try to avoid it," Penick said.

Some ants, including wood ants (Formica) and carpenter ants (Camponotus), have a distinct smell they use for defense in place of a stinger. "They can stop a bear with formic acid if they all come together and spray," Penick said. "But one on their own is just enough to give you a slight little wisp of vinegar." However, some people report not being able to smell formic acid; the ability to smell it may be genetic.

The final ant smell used to be controversial, but Penick said he and a colleague settled the debate with a 2015 study published in the journal American Entomologist. Odorous house ants (Tapinoma sessile) have long been regarded as smelling like coconut, or sometimes like rotten butter. But when Penick sniffed one for the first time, he was hit by the scent of blue cheese. So he shipped off the three foods — including butter that he let rot in his kitchen — and ant samples to a friend's lab, where a tool called a gas chromatograph analyzed the volatile compounds released into the air. Then, they compared the compounds that made up the smells of the foods and the ants. The team discovered a match between the ants and the blue cheese. 

At the same time, Penick had people rate what they thought the ant smelled like. Most people said blue cheese, but some thought it smelled like rotted coconut. So Penick rotted a coconut in his backyard and found a mold growing on it that, sure enough, is the same mold (Penicillium roqueforti) that's used to produce blue cheese. Another mystery, solved.

Originally published on Live Science.

Famed naturalist Edward O. Wilson, or E.O. Wilson, has died at the age of 92. The biologist, author and teacher was the world's top authority on the study of ants and called Charles Darwin’s "natural heir." 

Wilson died Dec. 26 in Burlington, Massachusetts, according to a statement released by the E.O. Wilson Biodiversity Foundation, a conservation organization Wilson co-founded in 2005.  

"E.O. Wilson’s holy grail was the sheer delight of the pursuit of knowledge," said Paula Ehrlich, CEO and president of the foundation. "A relentless synthesizer of ideas, his courageous scientific focus and poetic voice transformed our way of understanding ourselves and our planet."

Related: Image gallery: Ants of the world

Among his many titles, Wilson was honorary curator in entomology, the study of insects, and a research professor emeritus at Harvard University. He is the author of more than 430 scientific papers and described more than 400 species during his life. Wilson's legacy also includes being considered the founder of sociobiology, the study of the biological basis for social behavior, among other scientific disciplines and concepts. In 1976, he was awarded the National Medal of Science. 

Many people have paid tribute to Wilson and his work. Actor and environmental campaigner Leonardo DiCaprio wrote on Twitter: "The world lost a true hero for the planet when Dr. E.O. Wilson passed away - "the Darwin of the 20th century", prolific writer, pioneer of groundbreaking new concepts in biology, and one of the towering intellects of our time."

Wilson wrote about science for general audiences and published many books. He won two Pulitzer Prizes in general nonfiction for "On Human Nature" (Harvard University Press, 1978) and "The Ants" (Belknap Press, 1990), the latter of which he co-authored with Bert Holldobler. Wilson was also involved in conservation work, co-founding the Society of Conservation Biology and serving on boards for the Nature Conservancy, Conservation International and other organizations.

In his book "Half-Earth: Our Planet's Fight for Life" (Liveright, 2016), Wilson proposed dedicating half of Earth's surface to nature in order to preserve biodiversity and avert mass extinction. This idea is the basis for the Half-Earth Project, an E.O. Wilson Biodiversity Foundation program, working to conserve half of the Earth's land and sea. 

The E.O. Wilson Biodiversity Foundation did not give a cause of death but said a tribute to Wilson’s life will be held in 2022, with memorial details to be announced.

Originally published on Live Science.

Ants have social networks just like humans do, but instead of exchanging information through posts and comments, they vomit into each other's mouths. 

Most insects have a foregut, a midgut and a hindgut. "However, for social insects, the foregut has become sort of a 'social stomach,'" said Adria LeBoeuf, an assistant professor and leader of the Laboratory of Social Fluids at the University of Fribourg in Switzerland. Contents of the midgut and hindgut are digested, while contents of the foregut are meant to be shared, said LeBoeuf, lead author of a new study describing the findings.

Trophallaxis, or the act of regurgitating food into another organism's mouth, is very common in highly social species like ants. During a trophallaxis event, nutrients and proteins are passed from one individual''s social stomach to another's, and through a series of these exchanges, the ants create a "social circulatory system" that connects each member of the colony to everyone else, LeBoeuf said.

Related: 10 amazing things you didn't know about animals

Carpenter ants (Camponotus) constantly pass these nutrients to one another in this way. If you look at one colony, in a single minute you might see "20 trophallaxis events," LeBoeuf told Live Science. (An ant colony might hold at least thousands of ants.)

"About five years ago, we published a paper characterizing the fact that when ants do trophallaxis, they aren't just passing external food," LeBoeuf said, referring to a 2016 report in the journal eLife. "They are passing out hormones, nestmate recognition cues, small RNAs and all sorts of other things.”

So, by vomiting into each other's mouths, ants aren't simply exchanging nutrients, the study authors wrote. Instead, the ants are creating a digestive social network in which energy and information circulate constantly throughout the colony to be collected by the individuals that need these resources. This is much like how your brain can secrete a hormone and pass it to your circulatory system and it will eventually reach your liver. 

Lebouf thinks of a colony of ants not as a collection of individual ants, but instead as a “colonial superorganism,” where the colony essentially functions as if it were a body. Much like how a body has tissues and organs that perform jobs in support of a common goal, groups of ants with different jobs can be thought of as the tissues and organs of the superorganism. The foragers gather food, the nurses take care of young, the workers dig tunnels, etc. Organs use the circulatory system to pass around much more than food, so is it possible that the social circulatory system does more as well? 

"To help us understand why ants share these fluids, we explored whether the proteins they exchange are linked to an individual's role in the colony or the colony's life cycle," lead author Sanja Hakala, a postdoctoral fellow at the University of Fribourg, said in a statement.

For their most recent experiment, LeBoeuf and Hakala analyzed the social stomach contents of carpenter ants in both wild colonies and lab-raised colonies. Across their samples, they identified 519 proteins being passed around the ant colonies; 27 of those proteins were found in all of their samples, regardless of the colony's age, the colony's location or the individual ant's status.

The workers seem to be foraging for food, building that food into specific proteins and then passing those proteins around, LeBoeuf said. As a colony matures, more nutrient storage proteins — which act as a very concentrated food source — enter circulation, so older colonies have more of these proteins overall than younger colonies do, the team found.

"Often, adults in ant colonies don't even need to eat," LeBoeuf told Live Science. "Instead, they sort of slowly break down these nutrient-storing proteins."

Many adults in the colony don’t have to eat because there are ants that eat on behalf of the colony. 

"These findings show that some colony members can do metabolic labour for the benefit of others," Hakala said in a statement.

By analyzing what proteins were found where, LeBoeuf and colleagues could tell the difference between young and mature colonies, as well as differentiate wild and lab-raised colonies. which had a much lower diversity of proteins in their social stomachs than their wild counterparts. 

The role an individual ant plays in the colony can be determined by its social stomach contents, too, the team found. So-called nurse ants that care for young tended to have higher amounts of anti-aging proteins than other members of the colony, potentially to ensure that they survive to care for future generations. 

"We know now that things are produced in certain individuals, and they end up in other individuals, which is super exciting,"  LeBoeuf said. However, there are still many questions left to answer, she said. For instance, the team found that foragers had higher concentrations of nutrient storage proteins than nurses did but that nurses produced those proteins faster. The researchers aren't sure why this is.

LeBoeuf thinks studying systems like nutrient exchange in ants may help scientists better understand how metabolic labor is divided within individual organisms, as in, between the cells that make up a body. "It is hard to measure how metabolic work is shared between cells," LeBoeuf said. "Here, the ants pass things around in a way that we can easily access what they are sharing."

The findings were published Nov. 2 in the journal eLife.

Originally published on Live Science.

What do leafcutter ants and scores of middle-school students have in common? A mouth full of metal-laced teeth.

Tiny arthropods such as ants, spiders and scorpions routinely bite, sting or otherwise pierce tough material like wood and skin. It's a remarkable feat, given that humans have trouble chewing through so much as a piece of beef jerky (let alone a hunk of tree bark), even with our strong jaw muscles.

But new research has shed light on what gives one group of leafcutter ants (Atta cephalotes) their biting edge. Using powerful microscopes, scientists have discovered a web of zinc atoms woven into the biological structure of the ants' jaws, lending them the durability of a set of stainless steel knives, the researchers said. This smooth distribution of zinc allows the edge of the ant's teeth to form a fine point — and it keeps them sharp for a long time. 

Related: In photos: Trap-jaw ant babies grow up

"The tiny animals who had this material, their muscles are microscopic compared to ours," Robert Schofield, a biophysicist at the University of Oregon and lead author of the study, told Live Science. The trick, he said, is that ants and other metal-mouthed arthropods leverage their sharp chompers to apply precisely the right amount of cutting force to slice through leaves or hide.

Schofield and his team knew from prior research that ant teeth contained a lot of zinc. But they didn't know exactly how those metal atoms were arranged, and how that helped the ants' bite. By examining the material makeup of leafcutter ant teeth under an ion beam microscope before and after biting, the researchers were able to calculate the hardness, sharpness and durability of the teeth. 

An ant's jaw, or mandible, differs quite a bit from yours. "Ants don't rely much on mandibles to process food," said Cristian Klunk, an ecologist at the Federal University of Parana, Brazil, who was not involved with the study. But they do use them for pretty much every other task, from defense to home renovation, and so they need to keep them in tip-top shape.

Your teeth are covered in a layer of enamel, a calcium-rich material that is the hardest substance in the human body. If you looked at a bit of enamel under an electron microscope, you would notice calcium and phosphate molecules forming a chunky crystal matrix around carbon, hydrogen, and oxygen atoms. Those crystals are what keep teeth strong — but they're also what prevent them from being razor-sharp. 

In contrast, the tiny, serrated "teeth" lining the inside edge of an ant's mandible are coated in a smooth blend of proteins crisscrossed with zinc. This material, known as a "heavy element biomaterial" (HEB), easily matches human tooth enamel for strength. It also makes an ant's tooth much better for slicing and dicing, since the blocky calcium phosphate crystals found in enamel can't form extremely sharp edges — that would be like trying to fashion a knife "out of chunks of gravel", Schofield said. Zinc, however, does not form blocky crystals; instead it stays evenly distributed throughout the protein mixture. That fine consistency allows for the sharp edges of the teeth. 

Metallic reinforcements don't stop with ant teeth. Other invertebrates also weave zinc or a similar metal, manganese, into their tiny tool kits. Schofield and his team found that giant clam worms pack jaws infused with up to 18% zinc. Similarly, scorpion stings and spider fangs employ a mix of zinc and manganese atoms to ensure that these slender, needle-like structures can puncture tough flesh without breaking. 

Schofield and his team calculated that the addition of zinc or manganese to an invertebrate's exoskeleton reduced the amount of force they needed to pierce through tough material by 60% on average. "Because the zinc is more resistant to wear," said Schofield, "after a while, it becomes a huge difference."

The research was published Sept. 1 in the journal Scientific Reports.

Originally published on Live Science.

It takes a lot of teamwork to survive floods, and fire ants cooperate in the tens of thousands to build rafts of their bodies to float until the water subsides. Now, a time-lapse video shows how these crafty insects also create living conveyor belts on these rafts to help the riders reach dry land. 

The footage revealed how ant rafts changed their shape, with slender extensions of ants growing from the main sections of ant rafts like tentacles, over just a few hours. These bridges grew from the combined activity of two ant groups: so-called structural ants — insects that pack closely together to keep the colony afloat — that circulated to the top of the pile from the bottom, and surface ants that marched freely about on top of the rafts, which then moved into supporting positions underneath their friends and relatives.

Related: Image gallery: Ants of the world

There are more than 20 species of fire ants worldwide, but one species in particular,  the red imported fire ant (Solenopsis invicta), is known for its massive colonies of as many as 300,000 workers, according to North Carolina State University. 

If their underground tunnels flood, fire ants link together to create floating rafts that can hold together for weeks, if necessary, carrying the colony until waters recede. A fire ant's exoskeleton naturally repels water, and its rough texture traps air bubbles. Tightly knit ant bodies can, therefore, create a buoyant, water-resistant foundation for a floating raft, Live Science previously reported. 

Vast fire-ant rafts were numerous in southern Texas in the wake of 2017's record-breaking Hurricane Harvey. People who were also fleeing the storm's floodwaters were advised to steer clear of the rafts, as fire ants' venomous bites are extremely painful, Live Science reported that year. 

Prior research found that even after an ant raft's structure stabilized, its shape continued to change, with questing tentacles extending in multiple directions — but scientists didn't know how, exactly, that was happening.

"These protrusions have, to our knowledge, neither been documented nor explained in the existing literature," researchers wrote in a new study, published June 30 in the Journal of the Royal Society Interface.

They collected around 3,000 to 10,000 fire ants at a time and deposited the insects in containers of water with a rod in the center, around which the ants congregated and formed rafts. The scientists then filmed the ant rafts, capturing time-lapse and real-time footage of raft formation and shape changing. Image-tracking data and computer modeling revealed which parts of the ant raft were static and which parts were moving — and where all of the ants in the raft's different layers were going. 

The study authors found that the raft's exploratory tentacles were shaped by ant movement that the study authors called "treadmilling." As structural ants wriggled to the surface of the raft, free-walking ants would burrow into the lower structural levels. Together, this cycle contracted and expanded the raft, crafting narrow bridges of ants reaching outward to search for land nearby where the colony could safely disperse.

Other factors — such as the season, time of day and the colony's habitat — can influence ant behavior and could also play a role in the dynamics that shape fire ants' rafts. Those variables weren't explored in the experiments, but they could be investigated in future studies, the scientists concluded.

Originally published on Live Science.

Worker ants are known to take on many different job roles, from trash collectors to nurses that dress the wounds of injured comrades, to babysitters that care for their leader's young. But one Mediterranean ant species takes royal work to the extreme: The worker ants use their mandibles to haul their young queen to faraway nests so she can mate, according to new research.

Despite their miniscule size — around 0.1 inch (2 to 3 millimeters) — Cardiocondyla elegans ant workers have been observed carrying queens up to 50 feet (15 meters) from their home nests and dropping them off outside neighboring colonies. (That's about 5,500 times the ant's body length. If a 5-foot-tall (1.5 meters) person made the equivalent journey, they'd cover 27,500 feet, or more than 8,300 m.)

Scientists think that this piggybacking of queens to distant nests is the first recorded case of third-party matchmaking in animals; and it's all to avoid inbreeding.

Related: Gallery of crazy ants

"They need genetic diversity in order to survive," lead author Mathilde Vidal, a doctoral student at the University of Regensburg in Germany, told Live Science. "In other species, the male ants can just fly away, but here the males don't have wings and the queens won't use their wings. Neither will the queens leave the nests by themselves — it's up to the workers to carry them out."

Between 2014 and 2019, Vidal and her colleagues mapped out 175 Cardiocondyla elegans ant colonies across southern France; they observed how the worker ants carry the queens by gripping them firmly in their mandibles and hauling them on their backs, only releasing the queen once outside a foreign nest. 

After a queen has been deposited outside, the researchers found, she is permitted entry to the mating chamber, located near the nest entrance and filled with males — all of which are confined inside the chamber and accustomed to mating with closely related females. The outside queen then mates with the male ants, storing their sperm in a sac called a spermatheca for the rest of her life. 

Once the queen has successfully mated, she spends the winter in the foreign nest before being booted out in the spring to start her own colony, the researchers discovered. This behavior could be related to the ants' strict rules regarding resource allocation. It may be in the interest of a colony to look after a foreign queen that is carrying their genes, but workers will not tolerate more than one resource-intensive, egg-laying queen in a nest for too long; the workers can often become hostile, even murderous, to any queen that outstays her welcome. 

But the ant queen's story doesn't always end there. The researchers believe that some young queens get carried to multiple colonies by worker ants from different nests, mating with males from all of them. 

"In a nest with a lot of new queens to send out, the chances are that a worker will occasionally pick up an alien queen," said Vidal. 

Among most ant species, excessive inbreeding is usually counteracted through nuptial flights — single summer-day events during which winged males and females will take flight to breed in large swarms. But Cardiocondyla elegans' males are wingless and their queens' wings appear to be largely vestigial. So, in order to ensure a healthy mixing of genes, and a prudent scattering of relatives across their capricious and flood-prone riverbank habitat, workers must lend a helping mandible.

"Around 40% of the colonies can die every year," Vidal said of this particular species. "If they want to make sure their genes survive, they have to make sure they're well spread out."

Yet even with these zealous redistribution efforts, inbreeding still plays a vital role in the ants' reproductive cycles. Genetic experiments have revealed that two-thirds of all Cardiocondyla matings are between close relatives.

"These queens tend to mate with around eight males in their lives, four of whom, on average, are brothers," Vidal said. "Those other four can come from multiple colonies, but we don't know how many they're taken to on average yet."

Mysteries remain, such as what causes queen-laden worker ants to skip nearer nests in favor of those farther away, or what other rules could be governing workers' decisions on where they leave their queens. Answers to these questions could remain elusive until the researchers find a way to make the ants perform the carrying behavior in a lab environment. Still, the research highlights an interesting, seldom-observed fact about ant societies, and all societies in general: Rulers are as much an instrument of the ruled as the ruled are of rulers, and are dispensed with swiftly once they outlive their usefulness.

The researchers published their findings May 3 in the journal Communications Biology.

Originally published on Live Science.

Around 99 million years ago, a juvenile cockroach met a hellish fate. It was snapped up by the jaws of a Cretaceous hell ant, a fierce predator with long, curving mandibles that swept up toward the top of the ant's head. 

Just moments later, the ant and roach were trapped in sticky sap that eventually turned to amber, providing scientists with a first glimpse of how the weird-faced ants trapped prey. 

The profile of a hell ant, with exaggerated upward-facing jaws that arc like the Grim Reaper's scythe, is unlike that of any ant alive today. Adding to the facial weirdness is a hell ant's horn, which comes in a variety of shapes in this ant group, known as Haidomyrmecine.  

Researchers had long suspected that hell ants swung their prominent mandibles upward to catch their prey, unlike modern ants that snap their jaws together horizontally. In the piece of Cretaceous amber from Myanmar, scientists found the first confirmation of this hunting technique.

Related: Photos: Ancient ants & termites locked in amber

Hell ants lived during the Cretaceous period (about 145.5 million to 65.5 million years ago), and are known from amber deposits in Myanmar, France and Canada spanning 100 million to 78 million years ago, said evolutionary biologist Phillip Barden, an assistant professor in the Department of Biological Sciences at the New Jersey Institute of Technology. Barden and his colleagues described the amber-embedded hell ant in a new study, published online today (Aug. 6) in the journal Current Biology.

Scientists described the first hell ant about a century ago, and have since identified 16 species — all of whom have elongated mandibles and horns. 

In the amber, the mandibles of the hell ant Ceratomyrmex ellenbergeri hug the roach nymph, Caputoraptor elegans, from below, pinning it against the horn on the ant's head. Finding this rare example of fossilized predation was astonishing — but also vindicating, Barden told Live Science.

"When we first started working on hell ants in 2011 to 2012, it looked like the only way they could have fed was by moving their mouth parts vertically," Barden said. At the time, the notion was "a little contentious," but this little hell ant showed their hypothesis was correct, he said.

The researchers also digitally modeled the heads of Ceratomyrmex and other hell ants in 3D, comparing them to both  modern and extinct ants. Their analysis of the evolutionary relationships between the groups confirmed that hell ants were among the earliest known ants, according to the study.

Social digestion

The amber-trapped hell ant never got to eat the roach. However, Barden offered some diabolical possibilities for how that meal may have unfolded. 

"First thing would probably be that the ant would have stung the prey to paralyze it," he said. And how would it have eaten the roach? "We originally thought that all the hell ants would have pierced their prey and drunk the hemolymph, which is like insect blood," Barden said. However, while some hell ant species have horns that are reinforced for piercing, Ceratomyrmex's horn was holding the nymph in place but not piercing it.

The best potential explanation, Barden told Live Science, comes from the feeding habits of a modern ant from Madagascar called the Dracula ant (Adetomyrma venatrix), which also has oddly-shaped mandibles.

"They have these highly specialized mouthparts that are so exaggerated they can't feed themselves," Barden explained. "Instead, they feed the prey to their own larvae — and the larvae have unspecialized mouthparts, so they can chew normally."

Once the larvae are fed, what happens next truly seems like a scene from hell. Adult ants pierce the larvae's sides and they drink the hemolymph of their own offspring and siblings, a charming practice called non-destructive cannibalism, Barden said.

"Basically, they use their own siblings and offspring as a social digestive system," he said. "We don't have direct evidence that's the case here, but that could be something that's going on."

Originally published on Live Science.

Ants are a diverse group of insects well known for their ability to ruin picnics and invade kitchens. But out of the more than 12,000 different species of ants, there are many that play a vital role in ecosystem health. 

Ants belong to the insect family of Formicidae, within the order of Hymenoptera — the same order that includes wasps and bees. Although they're nearly ubiquitous now, ants were scarce compared to other insects when they first appeared on Earth between 140 million and 168 million years ago, according to The Field Museum. As flowering plants became more common, they provided new food sources for ants, which likely facilitated the insects' movement into new habitats.

Today, ants live pretty much everywhere, except Antarctica. They're the most dominant insect on Earth and scientists estimate that there are maybe another 10,000 species of ants left to discover. 

Related: 7 Insects You'll Be Eating in the Future

Ant anatomy

Ants are invertebrate insects with bodies that are divided into three main parts: head, thorax (where the three pairs of legs are attached) and abdomen (where the vital organs are located), according to Harvard University's Harvard Forest department. The ant's body is supported and shielded by a waterproof exoskeleton made of chitin, a hard fibrous substance. The two antennae on either side of the head serve as the ant's main sensory organs. Ants also have a pair of compound eyes that consist of many photoreceptors that allow them to see light and shadows. However, their eyesight is poor, and ants rely primarily on their sense of smell for understanding their environment. 

These hardy insects use a variety of pheromones, or chemical compounds, to communicate, according to a 2015 study published in the journal Scientific Reports. The ants produce pheromone trails that lead their fellow colony members to food or a nest, or to alert them to danger. Sensory receptors, mainly located in the antennae, can detect the differences in each type of trail or signal so the ant can respond accordingly.

Ants also have powerful mandibles that allow them to bite and cut through materials as well as carry heavy objects that are at least 10 times greater than their body weight, according to Harvard Forest. 

Ant species range in size from about 0.03 to 1.18 inches (1 to 30 millimeters), with the majority of species between 0.19 to 0.59 inches (5 and 15 mm) in length, according to the University of Michigan. The queen is the largest ant in the colony and lives the longest (several years). Males, on the other hand, are the smallest ants in the colony and typically live for only a few weeks. Worker ants, or non-queen female ants, can live up to a year. 

How do ants reproduce?

Male and young queen ants have wings, and they mate while flying, according to the Royal Society of Biology. Mating occurs in the summer when the conditions are warm and humid. Male ants die within a day or two after mating, while the young queens lose their wings and walk or dig to find a new nest. Queens are the only ants that lay eggs, and can live at least another 10 years in the safety of their nests, laying eggs for most of that time.

The male ants in the colony have the single job of mating, according to an article published by The Conversation. The sex of ants is determined by the number of genome copies within the egg. Unfertilized eggs contain a single genome and become male ants, while fertilized eggs contain two genomes and become female. 

Queens produce eggs that will become males and young queens only when it is time for new colonies to be formed, according to a 2004 study published in the journal Current Biology. After mating, the males will die, while the new queens will select a nest site to begin building their new colony.

Ant colonies

Ant colonies are often found underground, under rocks, in mounds or in trees, according to National Geographic. Some species create nests in wood, which can damage structures. A few others are more nomadic and don't have permanent homes. Colonies can range from just a few dozen members to over a million, according to the Australian Museum.

Most ant colonies contain a queen, workers (the adult daughters of the queen) and the young females who will eventually become workers, according to Arizona State University. Male ants don't do much except reproduce and are typically only around when needed for that purpose. Every ant has a job and contributes to the health of the colony. The queen lays eggs for nearly her entire life, the workers gather food and protect the colony and the young daughters care for the queen, eggs and larvae. 

Some colonies contain more than one queen, which eventually leads to competition and murder of other queens (by both queens and the loyal worker ants) until only one, or sometimes none, remain. 

What do ants eat? 

Most ant species are omnivorous and eat everything from plants, seeds and dead animals to engine oil, according to Antark. The pharaoh ant (Monomorium pharaonis), for example, likes a variety of sweets (such as sugar, cake and bread) and fats (such as butter and bacon), but also fancies shoe polish and used bandages, according to the University of Michigan Museum of Zoology. Similarly, the thief ant (Solenopsis molesta) eats insect eggs, other species of ants and insects, vegetables, seeds and fruits, according to the University of Michigan Museum of Zoology. 

Few species of ants are strictly carnivorous, such as army ants (Eciton burchelli), and they prey upon a variety of animals such as lizards, chickens, pigs and goats, according to Pests.org. There are also a few species of herbivore ants, such as the leafcutter ants, that eat a variety of plants and fungi, according to the San Diego Zoo.

Why ants are important

Around the world, ants play a role in keeping their local ecosystems healthy. For example, ants play a huge role in tropical rainforests by redistributing nutrients, according to a 2017 article published in the Journal of Animal Ecology. The authors estimated that more than half of the nutrient redistribution in the tropical rainforest of the Maliau Basin Conservation Area in Malaysia was performed by ants.

Ants also help turn and aerate the soil as they dig their tunnels, according to Iowa State University. This allows water, oxygen and minerals to better reach plant roots, allowing them to thrive. Ants also work as nature's gardeners by spreading seeds and fertilizing soil with nutrients from dead insects, animals and plants. 

Additional resources:

• Use the interactive map found at antmaps.org to learn more about where certain ant species live.
• Learn more about the social structure of ants in this video from TED-Ed.
• Read about one of the world's deadliest ants from National Geographic.

In an abandoned nuclear bunker in western Poland, hundreds of thousands of worker ants that fell inside and were cut off from the main colony survived for years by eating the bodies of their dead.

When researchers visited the bunker in 2016, they described a community of nearly a million worker ants of the species Formica polyctena, or wood ants. The main colony teemed above ground on a mound atop the bunker's ventilation pipe; over the years, a steady stream of unlucky ants fell through the pipe and into the bunker. Since the pipe opened into the chamber from the ceiling, once the ants landed on the floor, they couldn't climb back out. 

There was nothing for the ants to eat in the pitch-dark bunker; in 2016, the scientists hypothesized that the insects survived by cannibalizing their dead comrades. Recently, the researchers returned to the bunker to continue their investigation of the trapped ants, looking for evidence that the insects were eating the corpses of their nestmates. 

Related: Soviets Hid Nuclear Bunkers in Poland's Forests (Photos)

The bunker, once part of a nuclear base, is near the German border and was used by the Soviet military to store nuclear weapons from the late 1960s until 1992, the researchers reported in 2016.

"During an inspection made in July 2015, we estimated the size of the bunker 'population' of Formica polyctena to be at least several hundred thousand workers, perhaps close to a million," the scientists wrote online Nov. 4 in the Journal of Hymenoptera Research. While thousands of ants skittered over the bunker floor and walls, they were unable to walk on the ceiling where the pipe opening offered the only exit from their stone prison. 

There were no ant cocoons, larvae or queens in the bunker, so the queenless "colony" wasn't breeding. Rather, it continued to grow because ants continually fell through the open pipe whenever the main colony was active, the researchers reported. 

Worker ants would not typically branch off and form a new colony without a queen, but the ants trapped in the bunker "had no choice," the scientists wrote. "They were merely surviving and continuing their social tasks on the conditions set by the extreme environment."

Eat or be eaten

For the new study, the scientists collected more than 150 dead ants from "cemeteries" — piles of bodies on the floor and near the walls around the bunker's main ant mound. Bodies with gnaw marks on their abdomens were thought to have been cannibalized; sure enough, a "vast majority" — 93% — of the corpses showed signs of being eaten.

The ants' solution was a grim one, but cannibalism isn't uncommon in this species. Wood ants are known for waging "ant wars" — fierce battles with other ant species that are typically fought in the early spring, when food is scarce, according to the study. As corpses of fallen soldiers pile up, workers drag the bodies into their nests to feed developing young. In fact, "nestmate corpses can serve as an important food source not only in periods of food shortage," the scientists wrote.

In the bunker, the corpses served as a never-ending buffet, enabling the ants to survive in a location where they would otherwise have starved, the researchers said.

Gruesome as those conditions were for the bunker ants, their story has a happy ending (at least, for the ants that weren't eaten). The study authors also wondered if they could help the trapped ants find their way home, and in 2016, they installed a vertical "boardwalk" — a wooden beam extending from the floor to the entrance of the pipe. 

When the scientists returned to the bunker in 2017, they found that most of the ants had taken advantage of the new escape route. The bunker area that was previously crawling with hundreds of thousands of ants was "almost deserted," presumably with all the wayward ants finally reunited with their colony aboveground, according to the study.

• In Photos: Trap-Jaw Ant Babies Grow Up
• Gallery: Declassified US Spy Satellite Photos & Designs
• Photos: Top-Secret, Cold War-Era Military Base in Greenland

Originally published on Live Science.

Can you wrap your mind around the idea of a parasitic worm in an ant brain? If you can't, don't worry — there are photos.

Scientists recently captured the first images showing these "mind-controlling" parasites in action inside an unfortunate ant's head, revealing never-before-seen views of a deadly, brain-dwelling flatworm — the lancet liver fluke (Dicrocoelium dendriticum) — and uncovered clues to the worm's secrets of manipulation and behavior.

Lancet liver flukes target a wide range of ant species. Though they practice their mind-controlling tricks only on ant hosts, they pingpong among multiple species to complete their life cycle, according to the Centers for Disease Control and Prevention (CDC).

As eggs, they inhabit the dung of grazing animals like deer or cattle. After infected feces are eaten by snails, the worm larvae hatch and develop in the mollusks' guts. Snails eventually eject the worm larvae in slime balls, which are then gobbled up by ants. [8 Awful Parasite Infections That Will Make Your Skin Crawl]

Inside the ant is where the worm turns. Ants typically ingest multiple worms, most of which lurk in their abdomen. However, one worm makes its way to the ant's brain, where it becomes the insect's driver, compelling it to perform "absurd behaviors," scientists reported in a new study.

Under the worm's control, the now-zombified ant displays a death wish, climbing blades of grass, flower petals or other vegetation at dusk, a time when ants usually return to their nests. Night after night, the ant clings with its jaws to a plant, waiting to be eaten by a grazing mammal. Once that happens, the parasites reproduce and lay eggs in the mammal host. The eggs are expelled in feces, and the cycle begins anew, according to the CDC.

It's all about control

For years, biologists have been intrigued by the relationship between flatworm and ant, but the details of how the parasites manipulated ant behavior remained a mystery, "partly because until now we haven't been able to see the physical relationship between the parasite and the ant's brain," study co-author Martin Hall, a researcher with the Life Sciences Department at the Natural History Museum (NHM) in London, said in a statement.

That all changed when a team of scientists looked inside infected ants' heads and bodies using a technique called micro-computed tomography, or micro-CT. This method combines microscopy and X-ray imaging to visualize the inner structures of tiny objects in 3D, and in breathtaking detail.

The researchers decapitated preserved ants, removing their mandibles to get a clearer view inside their heads, then stained and scanned the ants' heads and abdomens, along with one complete ant body, they wrote in the study.

Their scans showed that an ant could have as many as three worms jockeying for control of its brain, though only one worm would eventually achieve contact with the brain itself. Oral suckers helped the parasites latch onto the ant's brain tissue, and the worms appeared to target a brain region associated with locomotion and mandible control.

Hijacking this area of the brain likely enabled the worm to direct the ant's death march and lock its jaws on a grass or flower anchor as it waited to be eaten, the study authors reported.

The findings were published online Tuesday (June 5) in the journal Scientific Reports.

Original article on Live Science.

The ants known as Sericomyrmex amabilis are humble farming folk. They tend thriving fungus gardens across Central America; raise big, hard-working families; and are always happy to let a neighbor drop in for a bite to eat — even when those neighbors are freeloading parasites and the "bite" includes a few of the farmers' babies.

Biologists estimate that about 75 percent of all S. amabilis nests also host a greedy parasite ant called Megalomyrmex symmetochus. These so-called social parasites show up to already-thriving fungus farms and can stay there for years, gorging on the farmer ants' crops — and sometimes their protein-packed larvae — without contributing a lick of work to the enterprise. And yet, through all of this, the farmer ants rarely raise a feeler to kick the buggy thugs out. Why not? [Photos: Ancient Ants & Termites Locked in Amber]

The reason for this awkward cohabitation, according to a new paper in the May 2018 issue of the journal Animal Behaviour, appears to be insect espionage with a dash of chemical warfare. Despite their freeloading, baby-eating manners, M. symmetochus ants have something their hosts don't: a potent venom that's been shown to scare off even more-aggressive invaders.

"It's likely a scenario where the enemy of your enemy is your friend," study author Rachelle Adams,an ant evolution specialist and assistant professor at The Ohio State University, said in a statement. Indeed, past studies have captured footage of M. symmetochus ants rushing to defend their hosts' fungus gardens from other invading species. 

In their new study, Adams and her colleagues built two lab-controlled S. amabilis nests: one that had been exposed to parasites, and one that hadn't. The researchers then watched what happened when new M. symmetochus parasites were introduced to the mix.

At first, the farmer ants seemed resistant to welcoming unfamiliar parasites to the nest. However, something caused the hosts to quickly change their tune. "When confronted with a parasitic ant, the farmer ant will at first lunge at the intruder, but then instead of biting, she'll pull away and bow her head down in a submissive response," Adams said.

Chemical analysis of both ant species revealed that the parasites had a distinctly different smell than the famers; this included traces of a potent alkaloid venom used to fight off even deadlier foes. The farmer ants can likely sense this venom from afar, the researchers wrote, and may have evolved to accept the parasites into their nests as a sort of mercenary defense force.

"Both the chemical profiles of parasites and the behavioral data support the hypothesis that the parasites use weaponry to maintain an amiable association with their host ants," the researchers wrote. In return for some occasional military support, parasites get a free place to crash, free meals and a sort of diplomatic ant immunity.

Once accepted into a host's nest, the parasites seem to tune down their venomous aroma and tread more stealthily. The researchers hypothesized that this might be the result of a common parasite tactic called "insignificance," in which the parasite emits a benign odor that literally smells like nothing to the host. Cloaked in the smell of nothingness, the parasite can essentially walk invisibly among the host's ranks. In summary, you could say that M. symmetochus ants tread softly and carry a big, venomous stick.

Still, this lopsided roommate arrangement doesn't always last forever, the researchers noted. In the lab and in the field, some host colonies have been observed rebelling against their parasite nest-mates after living together for more than seven years, either destroying the parasites entirely or severely culling their ranks. Further study into this seven-year insect itch is still required.

Originally published on Live Science.

Treetop-dwelling ants from Southeast Asia have an explosive defensive move: The insects take down their foes by blowing themselves up. If that sounds gut-wrenching to you, just imagine what it feels like to the ant.

Commonly known as "exploding ants," workers in this group respond to threats by deliberately (and fatally) rupturing their body walls, spattering rivals with toxic fluid.

Exploding ants are typically lumped together into a species group called Colobopsis cylindrical, but researchers recently determined that there are at least 15 species of these self-sacrificing insects — including one previously unknown species in Borneo, which they described in a new study. [Ants Scurry on 'Treadmills' for Science]

Many animals engage in chemical warfare, stewing toxic brews in their own bodies to subdue prey or scare off enemies. Venomous creatures — which include snakes, spiders, insects, fish, cephalopods, amphibians, reptiles and even some types of mammals — deliver their toxins with stings, stabs or bites.

But others, such as skunks, venom-squirting scorpions and bombardier beetles, opt to spray their chemicals. In fact, bombardier beetles can emit their heated, poisonous blasts even after they've been swallowed, with unfortunate results for their predator's digestion (and a sticky escape for the beetle).

However, defensively rupturing one's own body — a process called autothysis, from the Greek words for "self" and "sacrifice" — is somewhat more unusual, and is known only in ants and termites, the scientists reported.

Tick, tick, boom!

The new ant species — Colobopsis explodens — was formerly called "yellow goo," after the brightly colored gunk produced by its exploding worker ants. Their colonies can contain thousands of individuals, inhabiting the leafy canopies of trees that stand as tall as 197 feet (60 meters), and covering an area of at least 26,900 square feet (2,500 square meters), the study authors reported.

The researchers decided to make C. explodens a model species — one that scientists look at to draw conclusions about a larger group; in this case, exploding ants. They noted that C. explodens ants were "particularly prone to self-sacrifice" in the presence of threats — which included intruding researchers.

To blow themselves up, the reddish-brown minor workers — all sterile females — contracted a part of their abdomens called the gaster. They clenched it so tightly that it ruptured, spewing a yellow secretion that was manufactured in the ants' jaw glands and had "a distinctive spice-like odor," according to the study.

And suicidal explosions aren't the only weird adaptation in C. explodens. Major workers — the bigger "soldier" ants that are also sterile females — have enlarged heads with raised shield-like sections that are circular and flattened at the top. The oddly shaped heads create a perfect plug that the ants use to temporarily block openings into their nests, the scientists wrote.

The findings were published online today (April 19) in the journal ZooKeys.

Original article on Live Science.

A species of warmongering sub-Saharan ant not only rescues its battle-wounded soldiers but also treats their injuries.

This strikingly unusual behavior raises the survival rate for injured ants from a mere 20 percent to 90 percent, according to new research published Feb. 13 in the journal Proceedings of the Royal Society B.

These same ants, a species called Megaponera analis, were observed last year bringing their injured back to the nest, but no one knew what happened to the wounded ants after that, said study leader Erik Frank, a postdoctoral researcher at the University of Lausanne in Switzerland. Now, it's clear that the ants get extra TLC after being saved from the battlefield. [Mind Control: Gallery of Zombie Ants]

War ants

M. analis is a nondescript-looking species that lives in colonies of several hundred to over a thousand ants. They're skilled raiders, sending out columns of several hundred ants to attack termite nests and drag termite corpses back to their own nests for a feast. These raids, however, often come with a cost: ants with lost or crushed limbs, or even ants limping home with tenacious termites clinging to their bodies.

Frank and his colleagues knew from their previous work at Comoé National Park in northern Côte d'Ivoire that the ants assisted wounded comrades in getting home, but because the ants nest underground, they couldn't see what happened to the war-wounded after the raids. To find out, the team collected whole ant colonies and kept them in darkened artificial nests in the national park's research station. Infrared cameras kept track of the ants inside the nests.

The researchers then staged raids between the ants and captive termites, observing how the ants responded to heavily injured ants with five limbs crushed or amputated versus lightly injured ants with only two lost or damaged limbs.

Ant triage

They found that in the vast majority of cases, severely injured ants were left to die on the battlefield. This version of ant triage wasn't at the behest of the rescuers, Frank said; instead, ants with five missing limbs flailed, rotated and generally refused to cooperate with their rescuers. Ants with two lost limbs, on the other hand, curled up into easy-to-carry balls and let themselves be taken home. [Photos: Ancient Ants & Termites Locked in Amber]

"If you're able to stand up, you're very likely not too injured and you are still useful to the colony, so you should be able to call for help and be rescued," Frank said.

Once back at the nest, healthy ants would attend to the wounded, licking their injuries for sometimes up to minutes at a time. Ants that were prevented from getting this treatment had an 80-percent chance of dying within 24 hours, the researchers found, whereas ants that were cared for had only a 10-percent chance of death.

To find out what was killing the injured, untreated ants, the researchers relocated some to a sterile environment and found that only 20 percent died, indicating that infections are probably the biggest risk for injured ants.

"This seems to strongly suggest that the treatment inside the nest prevents an infection inside the wound," Frank said.

Any uninjured ant seems capable of providing the licking treatment — there's no indication of dedicated ant "medics," Frank said — but it's not yet clear whether the treatment prevents infections or actively treats them.

Either way, the behavior is exciting to see because it's extremely rare to observe any individual animal treating another's wounds in any species, Frank said. It's especially counterintuitive in ants, because the tendency is to think that ant individuals are easily replaced cogs in the machinery of the colony, he said. But in M. analis, colonies aren't that large, and only a dozen or so baby ants are born each day, Frank said.

"Losing one or two ants each day would be quite significant, so they really have to find ways to reduce the mortality in that sense," Frank said. "The individual does matter."

Original article on Live Science. 

Diseases can spread quickly among dense populations of organisms, whether they're people living in crowded cities or groups of social insects such as ant colonies. But some ant species are using homebrewed "antibiotics" to fight back.

To stop the spread of disease, some species of ants are known for producing antimicrobials — chemical compounds that kill pathogens — and researchers recently questioned how common this strategy is among these insects.

In a new study, scientists looked at species distributed across the ant family tree. Though it was widely suspected that all ants produced at least some antimicrobials, the researchers found that only about 60 percent of the species they investigated used antimicrobial agents to boost their colony's immunity.

Knowing which branches of ant lineages are antimicrobial producers could help fine-tune research for antimicrobials (which include antibiotics) that can be used in people, the scientists reported. [Image Gallery: Ants of the World]

When humans — or other animals with backbones and jaws — are infected with a pathogen, the immune system churns out proteins called antibodies that rally to the body's defense. Insects such as ants don't make antibodies — instead, they rely on other methods to repel microbial invaders, study co-author Adrian Smith, an assistant research professor of biological sciences at North Carolina State University, told Live Science in an email.

One such method is antimicrobial compounds, which the ants apply to their own bodies, to those of their nest mates and to their nests, Smith explained.

These compounds may be acquired from antimicrobial bacteria; for example, leafcutter ants are known to cultivate bacteria on their bodies that protect them against infection from parasites that feed on the fungus they grow as food. Other ant species produce antimicrobials from different internal glands, or harvest the ingredients from materials in their habitats such as tree resin.

Sharing these antimicrobials among the colony is an important aspect of the insects' communal behavior, Smith said.

"An individual’s success depends on the success of her colony," he said. "Having a means of socially controlling disease spread beyond an internal, personal resistance is crucial to maintaining a successful society."

Pinpointing pathogen protection

Previous research documented and described ants' antimicrobial use, but had yet to evaluate how widespread this was across ant species, the scientists reported in the new study. To find out, they looked at 20 ant species collected around Raleigh, North Carolina, testing workers to see if compounds found on their bodies would affect the growth of a bacterium called Staphylococcus epidermidis.

And the ants had a few surprises in store for the scientists.

The study authors expected to see all the social ants producing some type of antimicrobial compound, but 40 percent of the ants didn't appear to have any at all. The scientists also guessed that the strongest antimicrobials would be found in bigger ants, or in ants living in large colonies, which would be more vulnerable to disease outbreaks. However, the strength of the ants' chemical cocktails didn't line up with body size or colony size, the researchers reported.

In fact, the most potent antimicrobial was produced by one of the smallest ants in the study — Solenopsis molesta, also known as the thief ant — which also lives in some of the smallest colonies. 

So, what are these other ants doing to protect themselves — and their colonies — if they're not cultivating antimicrobials? It's hard to say for sure, but further investigation could uncover currently unknown methods for pathogen protection, which could open new avenues for fighting diseases in humans, Smith said.

"Some of the most useful lessons we can learn about disease resistance from ants might be those we least expect to learn," he said. "My bet is that those 'negative results' in our study are pathways to even more exciting insights into disease ecology."

The findings were published online Feb. 7 in the journal Royal Society Open Science.

Original article on Live Science.

Recently, researchers uncovered the adaptations that enable this superfast snapping in an elusive and little-studied genus of trap-jaw ants called Myrmoteras, using X-ray scans and high-speed video to analyze the ants' jaws in action — inside and out.

The scientists identified the latch, spring and trigger mechanisms for two Myrmoteras species, finding that their trap-jaw system operates in a manner unlike those in other groups of trap-jaw ants. [In Photos: Trap-Jaw Ant Babies Grow Up]

Myrmoteras ants are native to Southeast Asia and measure about 0.16 to 0.20 inches (4 to 5 millimeters) in length. They live and forage in leaf litter on the forest floor, which makes them difficult to find and capture while still alive, said study lead author Frederick Larabee, a postdoctoral research fellow with the Smithsonian AntLab at the Smithsonian National Museum of Natural History. It was previously unknown how fast the ants' jaws could snap closed and how exactly they worked, Larabee told Live Science.

When Myrmoteras' jaws are locked in the "open" position, as they are when the ant is hunting, they extend backward at a steep angle, pointing toward the ant's body. The Myrmoteras' ants' spiny, prey-catching mandibles are longer and more slender than those of their trap-jaw cousins, which suggests that Myrmoteras use these body parts to quickly stab and immobilize prey, rather than stunning them with a blow, the study authors wrote.

The scientists worked in the lab with several live colonies that had been previously collected, Larabee said. Footage shot at 50,000 frames per second revealed that the ants' jaws closed in about half a millisecond — not as quickly as ants in the trap-jaw genus Odontomachus, which snap their mandibles in one-tenth of a millisecond, according to the study.

But it was micro-CT scans — computed X-ray tomography — that enabled the researchers to detect and digitally model the inner workings of Myrmoteras' deadly strikes in 3D, the researchers said. 

"We wanted to be able to visualize all the internal structures — the muscles, the neurons, and the attachments between the muscles and the mandible itself," Larabee said.

Spring-loaded systems such as those found in trap-jaw ants have three main parts: a lock to hold the jaws open, a spring to store energy and a trigger to release the strike, transferring energy into the jaw to propel it closed at high speeds. Using CT scans, the researchers modeled the muscles responsible for opening and closing the jaws. Once the scientists knew what the muscles looked like, they could identify how they powered Myrmoteras' speedy bite, a process the researchers visualized in a video posted to YouTube.

The latch holding the jaws open was unlike any observed in other trap-jaw ants, resembling the locking mechanism in grasshopper legs, Larabee told Live Science.

Another unusual and unique structure that drew the scientists' attention was a strangely shaped lobe on the back of Myrmoteras ants' heads. The researchers noticed that it would compress immediately prior to a strike, hinting that the structure was part of the spring mechanism that released stored energy into the jaws.

"We're not entirely sure what the spring is, but we think it's the ligaments linking the muscle to the mandible," Larabee explained.

A spring-loaded jaw is a highly specialized feature, which makes it even more incredible that different ant lineages evolved such diverse structures to make these jaws work, Larabee said.

"All these ultrafast jaws, using different components or different body structures to serve this system — it's a great example of convergent evolution, where evolution has found different strategies for achieving the same behavioral goal," he said.    

The findings were published online Aug. 30 in the Journal of Experimental Biology.

Original article on Live Science.

A new science-fiction novel by author M. R. Carey features a team of biologists racing against time to find a cure for a zombie "plague" caused by a parasitic fungus, which is overwhelming human populations at an alarming pace.

But unlike most of the zombie-creating infectious agents that populate sci-fi stories, this one is grounded in horrific reality.

The hapless human zombies in "The Boy on the Bridge" (Orbit Books, 2017) are mindless automatons with only one objective on their minds — consuming human flesh and transmitting the zombie infection, caused by a parasitic fungus identified in the novel as "cordyceps." It was inspired by a real — and deadly — fungus genus known as Ophiocordyceps, which not only parasitizes ants but also hijacks their neural networks. These ant "zombies" behave in ways that are atypical for ants, but which help the fungus reproduce — in the end, the fungus bursts from the ant's body, killing its host. [Mind Control: Gallery of Zombie Ants]    

The novel's fictional fungus parasitizes people almost instantaneously, controlling them absolutely within moments of exposure through a zombie's bite. In a world already overrun by zombie cannibals, biologists under armed escort venture from the relative safety of a military base on a mission to collect data on the zombies, or "hungries," to find a weakness in the fungus that could help them develop a vaccine or a cure.

Among the biologists is a brilliant teenage boy, Stephen Greaves, who makes an astounding discovery about an unexpected symbiosis that evolved between the fungus and some of its human hosts — all of whom are children. That knowledge comes with a terrible price, driving him toward a decision that could threaten the lives of his colleagues, and endanger humanity's survival.

When Carey first considered the idea of a zombie plague, he quickly identified a promising candidate in an ant-parasitizing fungus featured in the 1995 BBC One documentary, "The Private Life of Plants," he told Live Science.

"The footage of the fruited body [of the fungus] emerging from the ant's head — it's absolutely horrific, spellbinding stuff," he said.

"The fungus doesn't affect any warm-blooded species — the idea that it could jump across so many biological barriers in one single bound is kind of ridiculous — but there's a hint in the book that there was some genetic manipulation going on," Carey said.

"If you accept that premise, it works really well. It neuro-hijacks an organism, shuts down higher brain functions, and turns human beings into feral animalistic machines with a single drive," he said.

40 million years of ant zombies

Real-world ants infected with Ophiocordyceps are eventually compelled to climb and attach themselves to plants in locations that are optimal for the fungus to release its spores. And the relationship between certain ant species and the fungus group Ophiocordyceps unilateralis — a complex of many species — is very old, dating to approximately 40 million years ago, João Araújo, a doctoral candidate studying the so-called zombie-ant fungus in the biology graduate program at Penn State University, told Live Science in an email.

Fungi in the Ophiocordyceps genus hold many fascinating questions for biologists. It is not yet known how the fungus chemically manipulates ant behavior, and researchers are still investigating the specific mechanisms of how the fungus takes over its host's body, Araújo said. [Zombie Facts: Real and Imagined (Infographic)]

However, scientists suspect that once spores penetrate an ant's exoskeleton, they immediately start to multiply and suppress the ant's immune system. Fungal outgrowths can be seen peeping from the ant's leg joints and from sutures in its exoskeleton within a single day, soon followed by the fruiting body of the fungus on a long stalk, Araújo said.

Once the ant is dead, the fungus continues to inhabit the corpse until its spores are ready to be released. How long that takes depends on the fungus species and where it lives — in the Amazon, that cycle can take a month or less, but in temperate regions that same cycle can take more than a year, according to Araújo. 

And like the unfortunate human hosts in Carey's novel, ants infected with the zombie fungus face a grim prognosis. Could they ever recover from zombification?

"Not that we know," Araújo told Live Science.

No happy ending

"The Boy on the Bridge" revisits a world that Carey first introduced in the short story that became the novel, "The Girl with All the Gifts" (Orbit Books, 2014), later adapted as a film by the same name that was released in 2017. The new story takes place in the decade before the first book, offering a glimpse of the circumstances that set the stage for humanity's last stand against fungus-controlled, cannibalistic zombies, Carey said.

The title character, Greaves, "functions as a bridge between humans and the hungries," Carey explained. "He stands a little way off from human society — partly because he's on the autism spectrum, and relationships present to him differently than they do to many people, and partly from the effects of trauma, from horrific bereavement at a very early stage in his life."

Without giving away too much, "The Boy on the Bridge" doesn't wrap up with humanity neatly eradicating the fungus and returning to the way things were, pre-zombies. Survival in nature, after all, frequently hinges on successful adaptation, which can mean that species take an unexpected evolutionary detour. That may sound bleak, but Carey still sees the story's ending as hopeful, he told Live Science.

"This comes from a position of almost near-despair when I look at the state of the world today — what we're doing to the environment, what we're doing to ourselves," Carey said.

"This world-spanning civilization that we've built over the last four to five thousand years is about used up. It either has to die or mutate into something else — it has to change into something different," he added.

"The Boy on the Bridge" is available to buy on Amazon.

Original article on Live Science.

"No killing moths or putting boiling water on the ants," the band Radiohead intoned in its creepy, computerized 1997 track "Fitter Happier." A new species named after the band would probably appreciate the sentiment.

Sericomyrmex radioheadi is a newfound Central and South American ant named to honor Radiohead for the band's conservation and climate-change awareness efforts. But the famous name isn't all that makes this ant special: It also grows its own food and is covered with a filamentous layer of white crystals.

Ants in the Sericomyrmex genus cultivate colonies of fungus in their nests, and this fungus protects the insects from parasites and serves as a food source. These ants are found all across Central America and in much of South America, but differentiating among the species can be difficult, researchers Ana Ješovnik of the Smithsonian Institution and Ted Schultz of the University of Maryland, College Park, wrote in their study, published today (April 24) in the journal ZooKeys. [Amazing Photos of Ants from Around the World]

Silken ants

The ants are striking under a microscope, thanks to the covering of velvety hairs that has given the insects the nickname of "silky" ants, the researchers said. But the ants are tiny and difficult to spot in the wild, Ješovnik and Schultz wrote. In an attempt to untangle the complicated taxonomy of the silky ants and to search for new species, the two researchers and their colleague Jeffrey Sosa-Calvo collected around 19,000 ant specimens from 17 different countries.

Previously, scientists had identified 19 species of Sericomyrmex and three subspecies, but the new analysis revealed that there are, in fact, only 11 separate species of these silky ants.

Three of those species are new, including S. radioheadi. One of the other newfound species, S. maravalhas, was found in the interior of Brazil and was named after the ant researcher Jonas Maravalhas of the Federal University of Uberlândia in Brazil, who provided specimens used in the analysis. S. saramama, the third newfound species, hails from Peru, Colombia and Ecuador, and it was named after Saramama, the Incan goddess of grain.

Crystal ants

S. radioheadi was discovered in the Amazonian region of Venezuela and got its name in part because the English band's music "is an excellent companion during long hours at the microscope while conducting taxonomic revisions of ants," the authors wrote. While all three of the newfound species look quite similar to the untrained eye, S. radioheadi is a lighter yellow than other silky ants; that coloration may have been a result of age, as all the species studied by the researchers were long-deceased ants from museum collections, the investigators said.

The researchers said they aren't sure why the newfound ant species all boast crystalline hairs, but added that the structures may have something to do with the ants' fungal gardens. Most fungus-cultivating ants grow beneficial bacteria on their bodies to repel parasites from their fungi, but Sericomyrmex ants don't do this, the scientists said. The researchers speculated that the crystalline hair layer could play some sort of anti-parasite role, instead.

Original article on Live Science. 

Hunting ants in Africa march off to raid termite nests with military precision. Now, new research finds that these ants are truly a band of brothers. They even rescue their wounded comrades.

These ant rescues aren't really selfless, researchers reported today (April 12) in the journal Science Advances. Without the fallen ants, colony sizes would probably be nearly a third smaller, because injured ants frequently die if they're not helped home.

"People always think that for ants or social insects, everything they do is for the good of the colony," said Erik Frank, a doctoral student at the University of Würzburg, in Germany, who led the research. Biologists typically downplay the importance of the individual insect, Frank told Live Science. [See Photos of Zombie Ants]

"Here we show, for the first time, an example where the good of the individual, of saving an individual ant, is good for the colony as well," Frank said.

Ants to the rescue!

Megaponera analis ants live in sub-Saharan Africa and eat termites — only termites. Multiple times a day, an ant scout will come across a foraging band of termites and rush back to its nest, recruiting as many as 500 ants to march to the termites and attack. The ants then carry the termite corpses back to the nest to feast. [Ancient Termite-Ant Warfare Locked in Amber]

But Frank noticed that some of the ants carried not dead termites, but living ants, back to the nest. Upon closer inspection, he realized that these ants were wounded. Some had lost a leg or an antenna, while others had an angry termite or two clinging to their bodies.

"What's the benefit?" Frank wondered. "Why were they even doing this?"

To find out, Frank first chose 20 random injured ants and forced them to return alone from the hunting site to their nest, without the benefit of help from their brethren. He found that 32 percent of the injured ants died on the journey. More than half (57 percent) of the injured ants that were killed were ambushed by jumping spiders because they couldn't move very quickly.

In comparison, only 10 percent of the healthy ants fell to predators on their marches back to the nest, and Frank never saw a carried ant get attacked in 420 raids.

For an injured ant, it was clearly beneficial to get rescued.

"But this is not the reason this behavior has evolved," Frank said. "It obviously needs to benefit the colony as a whole."

For the good of the group

And it does benefit the whole colony, Frank found. By marking injured ants with acrylic paint, Frank was able to track them in subsequent raids. He found that 95 percent of the time, the once-wounded ants returned to battle. In fact, 21 percent of ants in raiding parties showed signs of previous injury. Frank also found that ants with termites attached to them had those termites removed when they were safely back in the nest; ants that lost a limb or antenna spent a few hours figuring out how their bodies worked. By the next day, those amputee ants could run nearly as fast as their uninjured nest mates.

In 53 observed raids, Frank saw a total of 154 ants being carried. He estimates that a typical colony rescues between nine and 15 of its injured soldiers per day. A colony of M. analis ants produces only about 13 new baby ants per day, he and his colleagues wrote, so the rescues make a major impact on the ant colony's overall population.

A computational model that the researchers developed showed that without rescue behavior, colonies would likely be around 29 percent smaller.

"Instead of being forced to replace these injured workers with new ones, they can just keep using the injured ones," Frank said.

Further investigation revealed that a substance coming from injured ants' mandibular (jaw) glands seemed to prompt the rescue behavior. The pheromones released from the gland are a mix of dimethyl disulfide and dimethyl trisulfide, the researchers found. Healthy ants smeared with these compounds were promptly picked up and "rescued" by their nest mates.

In mammals, especially humans, empathy is often used to explain heroic or helpful behavior. The pheromone discovery reveals that ants have evolved another way to prompt helpfulness.

"We have the convergent evolution of two different mechanisms with the same end goal," Frank said.

Original article on Live Science. 

A zombie outbreak in a new apocalyptic film has an unusual inspiration — a parasitic fungus that causes zombie-like behavior in ants.

The fungus, Ophiocordyceps unilateralis, is one of about 200 species in its genus that grow on insects, and what it does isn't pretty: First, it invades a host's body, takes over its brain and then erupts from its body to disperse spores.

If you're wondering what that gruesome zombification process might look like in people, brace yourself for the movie "The Girl with All the Gifts" (Saban Films/Lionsgate, 2016), which opened on Feb. 24 in theaters in the U.S. In the film, a fungus similar to O. unilateralis transforms the world's population into mindless, flesh-eating zombies, called "hungries." Melanie, a young girl who is no longer entirely human (played by actress Sennia Nanua), emerges as humanity's last hope. [Zombie Ant Fungus Inspires Film ‘The Girl with All the Gifts’ | Video]

The film begins on a military base in Great Britain, with the outbreak already in its 10th year. Melanie and a group of children housed on the base attend a type of "school" where they are restrained in custom wheelchairs that keep them immobilized when they're around adults — and with good reason. All the children were born to women who were pregnant when the fungus infected them. Their offspring, while not overtly zombie-like, represent the next generation of hungries. They can think and move and act like normal people, but the scent of human flesh triggers the "hungry" response, turning the children into single-minded and deadly predators.

Adults at the site protect themselves from the youthful hungries with salves and clothing that mask their scent. But when the base is overrun by an outside horde of rampaging hungries, Melanie escapes with a group that includes her favorite teacher, Helen Justineau (played by Gemma Arterton), and biologist Dr. Caroline Caldwell (played by Glenn Close), who had been leading the military research to find a cure for the zombie infection. The future looks bleak as they travel the country and see the devastating extent of the outbreak, but Melanie may hold the key to their survival — and could determine the fate of the entire human race. 

Zombie science

From the start of the project, the filmmakers said they wanted a scientific explanation for their zombie apocalypse. The nature documentary "The Private Life of Plants" (BBC One, 1995) introduced them to a promising candidate — the fungus O. unilateralis, which parasitizes ants that live mostly in tropical forests, screenwriter Mike Carey said in a statement.

"The spores attach themselves to the ant’s body, and then the fungal mycelia grow up through the carapace of the ant into its nervous system. Basically, the fungus takes the ant and drives it away," Carey explained.

To translate that into how a human parasitized by a mind-controlling fungus might act, director Colm McCarthy searched for examples in the natural world.

"We looked at how grasses sway in the wind: The behavior of at-rest hungries was based on that," McCarthy told Live Science. "We wanted to create an impression for the audience that the hungries belonged in the natural world more than humans did."

The hungries' "activation" mode — when their hunting instinct is triggered by the smell of a nearby human — was inspired by an unlikely source: McCarthy's cat.

"When it sees insects or small birds, it starts to do this odd thing where it clacks its tongue very quickly," he said. "It's an instinctual feeding reaction that all cats have, and we thought that might be an interesting starting place for hunting behavior." [Zombie Animals: 5 Real-Life Cases of Body Snatching]

Neural takeover

The film's creators turned to biologist João Araújo, a doctoral candidate studying the so-called "zombie ant fungus" in the Biology graduate program at Penn State University, to act as the movie's scientific consultant and to ensure that the film correctly represented a parasitic fungus and how it manipulates its host.

For ants, zombification begins when they walk over Ophiocordyceps spores lying on the forest floor; the spores penetrate the ant's exoskeleton and invade its body, suppressing the immune system, Araújo told Live Science in an email.

"After 10 days, the fungus has spread within the host’s body and reaches the neural system, where it will release metabolites — we are all researching to know which metabolites — in order to control the host," he explained.

In the final stages of the parasite's growth, the ant is compelled to leave its nest and attach itself to a plant in a location that's ideal for fungus development; each fungus species guides its ant hosts to seek a particular type of plant as its final resting place, Araújo said.

The ant dies shortly after, and the fungus grows outward, sprouting from the ant's corpse and producing fruiting bodies that shoot spores into the forest undergrowth. Newly released spores germinate structures that attach themselves to other hapless ants, and the cycle begins all over again, according to Araújo. [Mind Control: Gallery of Zombie Ants]

An innocent zombie

Currently, there is no species of parasitic fungus known to affect humans, though Araújo described the possibility as unlikely but "very cool" — a perspective that is perhaps unique to those studying fungi that survive through zombification.

Another highly unusual element in "The Girl with All the Gifts" is Melanie herself — a child "hungry" who retains the essence of her humanity, even though she clearly has been changed by in utero exposure to her mother's parasitism.

"In most zombie films, the monsters are the bad guys and people are good guys. We've tried to make this film challenge that notion," McCarthy said. "In the same kind of way that Shelley's "Frankenstein" story has a tension between the monster and the idea of innocence, we've tried to do a story that has that kind of complexity to it."

"The Girl With All the Gifts" is available to rent online on YouTube and Google Play.

Original article on Live Science.

Scientists study how animals walk and run by putting them on treadmills  — from elephants and alligators to animals as tiny as an ant. Recently, researchers used a custom-made treadmill to study desert ants' fancy footwork, to better understand the mechanisms they use to navigate home.

This wasn't a scaled-down versions of the treadmill you'd find at a gym. Rather, the ants were tethered above a lightweight sphere. As the insects scampered forward — sometimes stopping and changing direction — the sphere would roll beneath them, and sensors recorded every step they took.

Using this equipment, researchers were able to reproduce ant homing behavior in a treadmill setting for the first time, analyzing the ants' movements in unprecedented detail to evaluate their walking speed and changes in gait as the insects searched for their nest. [Step Lively! Ants' Gaits Tracked on Treadmill | Video]

Spherical treadmills have been used in studies of small animals since the 1960s, but they have not been sensitive enough to follow the speedy motion of ants' tiny legs. For the new study, researchers built a treadmill made especially for ants. It incorporated a hollow, air-suspended Styrofoam ball that was highly responsive to the ants' movements, which the scientists tracked using optical mouse sensors.

"Our new design enables us to study the fast-running and very quickly turning desert ants," study co-author Matthias Wittlinger, a research fellow with the Institute of Neurobiology at Ulm University in Germany, told Live Science in an email.

The treadmill spins responsively as the ant walks; to keep the ant oriented but still able to move freely, tiny leashes made from a filament of dental floss were glued to the ants' back, then attached to pins that were suspended above the sphere. While this delicate attachment sounds tricky to perform, Wittlinger reported that it generally only took a few seconds to glue an ant to its tether.

Walk on the wild side

Ants were captured at a feeder located about 33 feet (10 meters) from their nest entrance, so they had already identified a route that would lead them back to the nest. Once they were placed on the treadmill, they trotted toward the nest's presumed location through mechanisms that prior studies had shown were critical to ant navigation: using the position of the sun and patterns of polarization in the sky as a compass, and calculating the distance by counting their own strides, Wittlinger said

The treadmill allowed the scientists to record the direction and speed of the walking ants; the flexible tether enabled the animals to move with a more natural body posture than had been possible in past studies — "Old designs had the animal rigidly fixed," Wittlinger said.

"They virtually travel for many meters on the treadmill, as if they were running in the open field," he explained.

The study authors reported that the ants would begin their treadmill journeys with a direct approach — heading straight for the nest. But when the insects didn't find the nest where they expected it to be, they adopted a different locomotion pattern, which Wittlinger identified as "search mode."

The study's findings showed for the first time that when ants realize that they're lost, they switch to "search mode," slowing down and then moving in a looping pattern, Wittlinger told Live Science in an email.

By reproducing conditions that test this complex behavior in ants — navigating home — in an artificial setting, the scientists could control and adjust a variety of parameters, to better understand the mechanisms and neural signals related to navigation, Wittlinger explained.

The findings were published online Feb. 15 in the Journal of Experimental Biology.

Original article on Live Science.

Foraging ants navigate so well, they can even do it backward, a new study finds.

Researchers had theorized that ants could memorize their landscape to navigate. However, the insects had been observed walking home in reverse, which contradicts the assumption that the ants relied on specific visual memory of the landscape to navigate. In a new study, scientists found that ants use both the landscape and clues from the sky to trek backward.

A team of scientists studied a colony of foraging desert ants (Cataglyphis velox). Though the ants would usually walk forward when carrying food back to the nest, they would move backward to drag larger items home, the researchers said. To test the insects' navigation skills, the researchers gave the ants either a small or large piece of cookie and placed them at a fork in the route to their nest. [Image Gallery: Ants of the World]

Regardless of their body orientation, the insects could make their way home, the scientists found. The researchers observed the ants using the sun and their memory of the landscape to maintain the correct route. The experiments also showed that ants walking backward would occasionally look behind them, checking their surroundings and adjusting course as needed.

"This suggests that they align their body forward to recognize the scene and to recover the direction," the study's co-first author Michael Mangan, a senior lecturer in computer science at the University of Lincoln in the United Kingdom, said in a video about the research. "They can then memorize this direction and subsequently follow it backward."

According to the researchers, these findings suggest ants have more complex spatial awareness. Rather than navigating relative to their own position, the ants seem to display an understanding of spatial relations in the external world, the scientists said.

"Ants have a relatively tiny brain, less than the size of a pinhead," study author Barbara Webb, a professor in the School of Informatics at the University of Edinburgh, said in a statement. "Yet they can navigate successfully under many difficult conditions, including going backward. Understanding their behavior gives us new insights into brain function, and has inspired us to build robot systems that mimic their functions."

In future studies, the researchers said the relationship between brain regions could be determined. This would not only offer insight into the insect's complex navigational skills, but could be applied to the development of computer algorithms to guide robots, according to the research team.

Results of the study are detailed in a paper published online Jan. 19 in the journal Current Biology.

Original article on Live Science.

Talk about intimate communication. Researchers have found that ants pass along chemical signals with their nest mates by sharing saliva.

The oral fluid of the Florida carpenter ant (Camponotus floridanus) contains chemicals that might help homogenize the scent of ants in the colony and even impact the growth of their larvae, researchers reported in a study published Nov. 29 in the journal eLife.

Previously, ants were thought to engage in the saliva-swapping, or "trophallaxis," mainly as a way to share food, study researcher Richard Benton, of the Center for Integrative Genomics at the University of Lausanne in Switzerland, said in a statement.

"But trophallaxis occurs in other contexts, such as when an ant is reunited with a nest-mate after isolation," Benton said. "We therefore wanted to see if the fluid exchanged by trophallaxis contains molecules that allow ants to pass other chemical messages to each other, and not just food." [See Photos of Crazy Ants in Florida]

Collecting ant spit

To answer that question, the researchers had to find a way to collect ant spit. This was no easy task. Instances of trophallaxis happen quickly and are impossible to predict, making a wait-and-see approach impossible, the researchers wrote in eLife. First, the team attempted to prompt trophallaxis by feeding an ant sugar solution and temporarily isolating it from its friends, a condition that did prompt more ants to share spit. But that method was still low-yield, and was prone to potential confounding variables, the researchers wrote: The ant oral fluid might be altered by the sugar feeding or by the effects of isolation.

So the team came up with another approach. They anesthetized ants temporarily with carbon dioxide and then squeezed them gently to squirt out a bit of spit. They compared this fluid to the small amounts of saliva they'd collected by the sucrose method and to the ant gut contents and circulatory fluid to be sure that what they were collecting was the same oral fluid swapped during trophallaxis.

Once they knew they had the right stuff, the researchers used mass spectrometry, a method that measures the mass of molecules inside a sample, in order to identify the components of the fluid. They found far more than food — the ant spit contained dozens of proteins, 64 microRNAs (small segments of the molecule that helps translate genetic instructions into proteins and other building blocks of the body) and long-chain hydrocarbons that may help install a colony's signature scent on individual ants, an important signal for identification and social interactions. The study couldn't yet prove, however, that trophallaxis directly influences the ants' scents or immunology.

Special saliva

Many of the proteins in the oral fluid are digestion-related, but at least 10 are involved in the regulation of growth and development, the researchers reported. Among these proteins were ones that make up juvenile hormone, a chemical important for insect development and behavior. Further analysis revealed that juvenile hormone was present in the ant oral fluid. [Photos: 15 Insects and Spiders That May Share Your Home]

This is important because trophallaxis is how ant nurses feed developing larvae; the presence of the growth hormone in their spittle might play a role in larval development. To test that idea, the researchers selected some adult ants and fed them either food supplemented with juvenile hormone or with an inert substance. The ants were each given five to 10 larvae to raise. Those nurse ants supplemented with juvenile hormone raised larvae that were larger in adulthood than the larvae raised by the control group. They were also twice as likely as the control larvae to successfully complete metamorphosis to develop into adults.

"When the ants feed their larvae, they aren't just feeding them food, they are casting quantitative ballots for their colony, administering different amounts of growth-promoting components to influence the next generation," study author Adria LeBoeuf, also of the University of Lausanne's Center for Integrative Genomics, said in the statement.

"Our findings suggest that trophallaxis underlies a private communication channel that ants use to direct the development of their young, similar to milk in mammals," LeBoeuf said.

Original article on Live Science. 

Scientists have recently discovered a mysterious, 100-million-year-old insect trapped in amber — and as far as anyone knows, it is unlike any other insect that has ever lived on Earth.

The weird insect, called Aptenoperissus burmanicus, is a mash-up of many other creatures: It has the face of a wasp but no wings, the legs of a grasshopper, the antenna of an ant and the body of a cockroach.

"When I first looked at this insect, I had no idea what it was," study co-author George Poinar Jr., a professor emeritus at Oregon State University, said in a statement. "You could see it's tough and robust, and could give a painful sting. We ultimately had to create a new family for it, because it just didn't fit anywhere else. And when it died out, this created an evolutionary dead end for that family," added Poinar, who is one of the world's leading experts on fossils preserved in amber. [In Photos: Amber Preserves Cretaceous Lizards]

Trapped in amber

The stunningly preserved female specimen was found in the Hukawng Valley in Myanmar, encased in amber. Scientists working in the region have found hundreds of other well-preserved creatures trapped in amber, all from the Cretaceous Period.

When they discovered A. burmanicus, Poinar and his colleagues spoke with several experts, all of whom were stumped by the insect's odd combination of features.  

"We had various researchers and reviewers, with different backgrounds, looking at this fossil through their own window of experience, and many of them saw something different," Poinar said.

Eventually, the researchers created the new family classification, Aptenoperissidae, within the order Hymenoptera. As such, it is only distantly related to other members of the order, such as bees and wasps. It is now the only known species in that family, the researchers reported in a forthcoming issue of the journal Cretaceous Research.

"If you focused on its strong hind legs, you could call it a grasshopper. The antenna looked like an ant, the thick abdomen more like a cockroach. But the face looked mostly like a wasp, and we finally decided it had to be some kind of Hymenoptera," Poinar said.

Though the researchers know relatively little about this odd creature's lifestyle, they said it probably crawled along the ground to lay its eggs, and used its stinger to hunt grubs. It's not clear exactly why the bug went extinct, though its inability to fly could be a potential reason, the researchers said.

Either way, when the creature died out, it became an evolutionary dead end, as there are no known close relatives, either past or present, for this mysterious insect.

Original article on Live Science.

A dragon from "Game of Thrones" has come to life — sort of.

A new ant species' dragon-like appearance inspired scientists to name it for the fire-breathing star of the popular fantasy series. The Pheidole drogon's large and distinctive spine reminded researchers of Drogon, one of the dragons on the "Game of Thrones" TV show, adapted from the novels written by George R. R. Martin.

The ant's spiny characteristics were captured in detail using 3D-imaging technology, which the researchers employed to help identify and document several new ant species. Their findings were published in two different papers published online today (July 27) in the journal PLOS ONE. [StarStruck: Species Named After Celebrities]

"This is one of the first studies in ant taxonomy to use micro-CT," study co-author Evan Economo, head of the Biodiversity and Biocomplexity Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), said in a statement. "While this method is gaining popularity in different scientific fields, it is rare to use it in this way."

Taxonomy — the process of identifying, documenting and naming new species — traditionally involves photographs, drawings and verbal descriptions of the species. By using X-ray microtomography, a 3D-imaging technology similar to CT scans used in hospitals, scientists can create virtual representations of specimens. These digital copies can then be dissected, archived and shared.

Now, scientists around the world can study Pheidole drogon without traveling to the tropical rainforests of Papua New Guinea, where it was found, or a museum to see it in a collection.

It's almost the same, if not "better than the real thing," Economo said. "Because you can virtually dissect the specimen and examine [the] internal structure on your computer."

Virtual specimens were also used by the researchers to study the ant's dragon-like spine. They discovered that along with the obvious defense function, the spines were filled with muscle, which makes the ants stronger than their nonspiny counterparts.

Original article on Live Science.

A new species of spiny ant with intricate, wrinkled skin has been found in the Singaporean rainforest.

Myrmecina magnificens, named for its beauty, lives in leaf litter on the forest floor and probably preys on tiny mites, said discoverer Mark Wong, an ecologist and independent researcher in Singapore. It has skin with a fingerprint-whorl pattern and delicate golden spines that point, unusually, toward the front of its body.

"Some people say it looks a little bit like a fearsome raisin," Wong told Live Science. [Cool Close-Up Photos Show Ants of the World]

Sifting the leaves

Wong found the new ant in his free time; he's been working to describe new ant species in the little-studied primary rainforests in Singapore, where logging has been limited and there has been little research on ants in decades, he said.

He found M. magnificens by collecting and sifting through a sample of leaf litter. The detritus on the forest floor is home to many species, Wong said.

"It's where you're most probably going to find something interesting," he said.

After discovering the unknown species in this way, Wong captured some additional ant workers by baiting traps with tuna and burying them 2 inches (5 centimeters) under the soil. In total, he captured and described five individuals of the new species.

Part of the ecosystem

The new ant measures about 0.18 inches (4.5 millimeters) long. This is the first known species of Myrmecina ever discovered from the Malay Peninsula, Wong and his co-author, Benoit Guénard of the University of Hong Kong, wrote in the Journal of Hymenoptera Research on June 27. The Malay Peninsula contains the southernmost tip of Myanmar, Southern Thailand, West Malaysia and Singapore. 

Tiny, urbanized Singapore might seem like a strange place to find new species, Wong said. But it's a good spot to look, because the rainforests there are relatively unaffected by human activities such as logging, he said.

M. magnificens is also the first of its genus to sport front-facing spines, Wong said. Some other members of the group have similar spines, but they all face backward. Researchers aren't sure what the fingerprint pattern is for, Wong said. It might help ants trap chemical compounds called pheromones (used for communication) near their skin, or it might help keep the ants from drying out. But so far, that's speculation, Wong said. Likewise, the spines might be used for defense, but researchers aren't sure. 

Similarly, little is known about the new ant's lifestyle. Other Myrmecina species eat tiny moss mites and nest in small colonies of fewer than 100 individuals.

There have been about 15,000 species of ants described so far, with many species still undiscovered, Wong said. (He's documenting the species of Singapore up-close on his Instagram feed.) These tiny creatures are crucial for recycling nutrients back into forest soil, he said, and because of the link they occupy in the food chain. In Southeast Asia, for example, the critically endangered Sunda pangolin (Manis javanica) eats a diet heavily reliant on ants.

M. magnificens, isn't the only ant to make use of colorful hairs. The Saharan silver ant boasts silver "fur" that reflects sunlight like a mirror, keeping the desert ants cool.

Original article on Live Science.

Editor's Note: This article was updated to correct the area where the ant lives and also to clarify that it's the fingerprint pattern that scientists are puzzled about. 

A bizarre Amazonian butterfly is the ultimate freeloader, researchers say.

The butterfly species steals and eats gooey bamboo secretions from its ant neighbors, in a relationship known as kleptoparasitism, new research has found.

"They're kind of jerks at the adult stage," said study co-author Aaron Pomerantz, a field biologist at thenextgenscientist.com. "They're just stealing a resource, and they're getting away with it for now."

Pomerantz and his colleagues have now captured images of the odd behavior — the first time that kleptoparasitism has been documented between adult butterflies and ants. [See Gorgeous Images of Butterflies Stealing Ant Goo]

Long-standing relationship

The goo-stealing butterflies, Adelotypa annulifera, are a wide-ranging species thatlives in a swath of South America from Bolivia to Guyana.

In 2013, Pomerantz's colleague Phil Torres was taking photos in the Amazon forest near the Tambopata Research Center in Peru when he noticed the butterflies feeding on bamboo sap where ants were congregating.

Torres told Pomerantz about it, and the two soon realized that although the species had been identified a century earlier, almost nothing was known about the life cycle of this butterfly.

"We had no idea what the caterpillars looked like; no one had ever seen them before," Pomerantz said.

So, upon returning to the site, Pomerantz went on a hunt to find the caterpillars of the species. He spent many weeks looking through the bamboo forest where Torres had originally found the creatures.

"Finally, I peeled back this little leaf, and that's when we saw the larvae," Pomerantz said.

As they returned over and over again to study the butterflies and ants, they noticed that the two species stuck together through all of the butterflies' life stages, from larvae to adults, the researchers reported in the June issue of the Journal of the Lepidopterists' Society.  

Still freeloading as adults

When the relationship starts out, it seems to be more of a two-way street. Multiple ant species — even those known as bullet ants, which deliver the world's most painful sting — offer bodyguard duty while the caterpillars give the ants a nutritious "protein shake" of amino acids and sugars through a specialized body part called the tentacle nectary organ.

Caterpillars from the same family, called Riodinidae, even lure ants by singing to them with a special vibratory organ. (The caterpillar songs are too quiet for humans to hear them without specialized equipment.)

But as adults, the butterflies become freeloaders. The butterflies sport bright-red dots on their wings — a pattern that mimics stinging ants — allowing them to disguise themselves as ants and avoid predators, Pomerantz said.

"The butterflies aren't all that skittish; they just hang out in the open, and that's uncommon for a lot of butterflies," Pomerantz said.

Even worse, the butterflies physically block the ants from feeding on the bamboo sap, hoarding all the goo for themselves. Meanwhile, researchers are unsure whether the ants get anything out of the relationship.

It's not clear why the adult ants tolerate this thievery, but one possibility is that the ants simply can't figure out what's going on. Ants have poor eyesight and typically communicate with each other via chemicals such as pheromones.

"Over evolutionary time, a lot of critters have figured out how to hack their chemistry so they can hang out with them," Pomerantz said, referring to ants.

Therefore, it's possible that the caterpillars continue to release "come hither" friendly pheromones even as they mature into adults, tricking the ants into tolerance, the researchers speculated.

Original article on Live Science.

Butterflies and ants

A new study has revealed a strange relationship between an Amazonian butterfly species and its neighboring ants — the butterflies steal the ants' yummy and nutritious goo. Here's a look at the first images showing a behavior called kleptoparasitism between adult butterflies and ants.

[Read the full story on the butterfly-ant relationship]

Butterfly mooches

Researchers Aaron Pomerantz and Phil Torres encountered the bizarre relationship while working at a field station in the Peruvian Amazon. They noticed that the butterflies were always spotted hanging around ants, and wanted to understand why.

Elusive species

Though the butterfly species, Adelotypa annulifera, was discovered a century ago, little was known about its life cycle. So the researchers set out to find the larvae, or caterpillar of the species, which had never been spotted before.

[Read the full story on the butterfly-ant relationship]

Bamboo dwellers

After weeks of research, the team peeled back a leaf on a bamboo plant and found the larvae, then studied their behavior to understand their life cycle.

Larval features

The team took stunning photos of the insects throughout their life cycle, and found that the caterpillars have a tentacle nectary organ, which produces a nutritious mixture of amino acids and sugars that ants often feed on.

Protein snack

It turns out that the caterpillars and a ants may have a mutually beneficial relationship. The caterpillars produce a tasty snack of amino acids and sugars, and the ants do bodyguard duty for the caterpillars.

Ants and larva

Here, an ant and caterpillars of the species nestle together inside the bamboo leaf.

Ants watch over the larvae

Here, bullet ants, which are known for their painful stings, watch vigilantly over the caterpillars.

Gooey treat

Here, the larvae hang out in close association with the ants.

[Read the full story on the butterfly-ant relationship]

Ants and caterpillars

The ants and caterpillars interact.

[Read the full story on the butterfly-ant relationship]

One-way street

As the caterpillars morph into butterflies, however, the relationship changes. The butterflies continue to mooch off the ants, stealing the sticky sap of the bamboo plant from the ants.

Mimicry for self-defense

It's not exactly clear why the butterflies sport red dots on their wings, but one possibility is that they are trying to mimic the ants, thereby deterring predators from turning them into a tasty snack.

Stuck in a bad relationship

It's not exactly clear why the ants tolerate the freeloading from the butterflies.

[Read the full story on the butterfly-ant relationship]

Chemical communicators

One possibility is that ants have poor vision and communicate by smell, meaning that if the caterpillars continue to secrete friendly pheromones into their adult stage, the ants may not notice that the butterflies have been

Ant does bodyguard duty

Here, an ant does bodyguard duty for the larva.

[Read the full story on the butterfly-ant relationship]

Ant and butterfly

An ant gets some air hanging out on the wing of the Adelotypa annulifera butterfly.

Adult butterfly

Here, the adult butterfly rests on a leaf.

Hands off!

Here, a butterfly and an ant hang out together on a bamboo leaf.

[Read the full story on the butterfly-ant relationship]

It's weird enough that some ant species can work together to build living rafts in the event of a flood. Now, researchers find that individual ants have assigned seats on these life rafts — and they remember them again and again.

The floodplain-dwelling Alpine silver ants (Forica selysi) cluster together when the waters rise, creating a living life boat that surrounds and protects the colony's queen. Fire ant species make similar rafts, clinging to one another with their jaws, claws and sticky leg pads. Researchers call this process "self-assembly."

To understand how Alpine silver ants pull off this remarkably cooperative feat, researchers at the University of California, Riverside, and the University of Lausanne in Switzerland marked the abdomens of ants with different colors of paint. They then subjected the insects to mock floods and video-recorded them swarming into floating masses. [See Cool Photos of Crazy Ants]

The color-coding allowed the researchers to track where individual ants ended up in the rafts: base, middle, top or side. They found that the ants were remarkably consistent. Eighty percent stayed in one location in the raft for the full 30-minute experiment. More to the point, the ants returned to the same locations in the raft over the course of two separate floods (though ants in the base and along the sides of the raft sometimes swapped positions).

When pupae, or baby ants, were included in the rafts, the worker ants tucked these vulnerable members of the colony in the middle of the rafts. In these experiments, more worker ants ended up along the base and on the top of the assemblages than other spots, creating something like a floating ant sandwich.

It's unclear how the ants decide their positions in the rafts, the researchers wrote April 7 in the journal The Science of Nature. The positions may be based on size and job description, for example, with nurses (responsible for the pupae) on the bottom and slightly larger foragers on top. Age and even individual personality of each ant might also play a role, the researchers wrote.

"These elaborate rafts are some of the most visually stunning examples of cooperation in ants," study researcher Jessica Purcell, an entomologist at UC Riverside, said in a statement. "They are just plain cool. Although people have observed self-assemblages in the past, it's exciting to make new strides in understanding how individuals coordinate to build these structures."

Follow Stephanie Pappas on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science.

One ant species in the Sahara Desert is covered by a silvery sheen of body hair that acts as a wearable sun shield for the creatures, a new study finds.

The silvery hairs completely reflect the light like mirrors, preventing the ants from absorbing too much heat. That may help to explain how the Saharan silver ants can stay cool when temperatures in the arid region reach a blistering 122 degrees Fahrenheit (50 degrees Celsisus).

"The ability to reflect solar radiation by means of total internal reflection is a novel adaptive mechanism in desert animals, which gives an efficient thermal protection against the intense solar radiation," study co-author Serge Aron, an evolutionary biologist at the University Libre de Bruxelles in Belgium, said in a statement. "To the best of our knowledge, this is also the first time that total internal reflection is shown to determine the color of an organism." [See Photos of Crazy Ants]

Hot weather, cool bodies

The Sahara is the hottest large desert on the planet and one of the most punishing environments for any creature to withstand. Comprising millions of square miles of sand dunes that cover 10 African countries, the area is inhabited mostly by myriad small and scurrying creatures, such as rodents, snakes and scorpions.

One of these native creatures is the Saharan silver ant. These shiny ants are known to be well-adapted to Sahara's withering heat. Scientists had shown in past research that the ants' silver hairs played a role in preventing overheating, but they weren't sure exactly how that worked.

To answer that question, Quentin Willot, an evolutionary biologist at the University Libre de Bruxelles, Belgium and colleagues took a very close look at the ants' hairs. The team analyzed the path of reflected light inside the silvery hairs under a scanning electron microscope, then compared that to the light path in the ants that had been shorn of their hairs.

Those ants sporting a luxurious patch of hair were 10 times as reflective as their shaved brethren. What's more, the team found the silvery hairs formed a kind of prism, which forced light rays entering the hair to be completely reflected off the bottom surface, rather than passing through and entering the ant's body. The prism effect occurs thanks to the triangular cross-section of the hairs, the researchers reported yesterday (April 13) in the journal PLOS ONE.

These adaptations seem to work: The silver-haired ants kept their bodies up to 4 degrees F (2 degrees C) cooler than the shaved ants did.

Though other ants and related species also sport protective bristles, most have cylindrical or plate-like cross-sections, meaning the internal reflection achieved by the Saharan silver ant may be unique, the researchers said.

Follow Tia Ghose on Twitter and Google+. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

About 18 million years ago, army ants that were adapted to living underground — and had lost much of their sight — returned to the surface and regrew the parts of their brains related to vision, a new study has found.

But the brain benefits didn't end there. Not only did the ants recover a set of previously underused brain structures, but their overall brain size increased as well. In turn, this brain-size increase enhanced the ants' sensory input capabilities as well as their processing centers to handle a more complex environment.

I can see clearly now

The army-ant subfamily Dorylinae dates to about 78 million years ago, and most of these ants live underground at least part of the time; their eyes are either very small or completely absent. In the study, the researchers noted that this subfamily descended from a large-eyed ancestor whose vision capabilities and vision-related brain regions dwindled over time — a transition that occurred repeatedly within the ant lineage.

But what happened to one branch of the army-ant family was extremely unusual: After living underground for 60 million years, army ants from the Eciton genus headed back into the light, and over time, their brains changed dramatically as they adapted to living on the surface.

The researchers found that the optic lobes of surface-dwelling Eciton army ants were significantly larger than the optic lobes in their underground cousins. The regions of their brains dedicated to processing smell were larger, too, and the ants' brain volume increased relative to their body size. [Cool Close-Up Photos Show Ants of the World]

These structural changes suggested to the researchers that the growth in the ants' changing brains was being driven by a range of environmental stimuli, such as variations in activities based on the day-night cycle, an increased threat of predators and greater prey diversity.

Brain-picking

Study co-author Sean O'Donnell and other researchers in his lab have been investigating army-ant diversity and ecology since 2003. O'Donnell, an evolutionary biologist and professor in the Drexel University Biology Department in Pennsylvania, told Live Science in an email that he and his colleagues were eager to explore an aspect of army-ant biology that was previously unknown: how much the brains of ants that lived aboveground differed from those of ants that lived underground.

"Similar studies on other groups of animals — cave fish and their relatives, subterranean insectivore mammals — suggested they [army ants] were a great place to look for evolutionary changes in brain structure," he said.

O'Donnell explained that peering at the brain of an ant — and in the species they sampled the most, that's about the size of small sand grain — involved a lot of preparation by a skilled and dedicated lab team. After preserving the ant with a fixative, they embedded the tiny head in resin, sliced it into sections, and then stained and photographed the tissue. Once the scientists had the photos, they measured the brain structures and then calculated their volume by stacking the slices and multiplying by their thickness.

O'Donnell and his colleagues suggested a few aspects of the aboveground world that are more complex and require the evolution of extra brain space: a diversity in prey, the presence of predators, and the variation between daytime and nighttime activities.

The large brains and enhanced optic lobes in Eciton ants were exceptional for any species of army ants, but the researchers found that Eciton ants had even more surprises in store. Even though they sported working peepers, their eyes seemed to differ from those of other insects.

"One exciting pattern we uncovered is the suggestion that Eciton eyes are functional but seem to have [a] peripheral and neural structure that is distinct from most insect eyes," O'Donnell said. "We are keen to explore how their eyes function."

The findings were published online March 8 in the journal The Science of Nature.

Follow Mindy Weisberger on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science