Back when dinosaurs stomped the Earth, dinky mammals scurried about in their shadows. The little furballs, hiding out in underground burrows, provided a fresh niche for a novel reptile: the snake. Skinny snakes could squeeze into the homes of mammals and gobble them up.

At least, that's how the dawn of snakes is imagined by Marc Tollis, an evolutionary biologist at Northern Arizona University in Flagstaff. No one knows for sure. Like the creatures themselves, the snake fossil record is long and thin, leaving gaps in snaky history. Major questions, such as where they got their start and who their closest relatives are, remain unanswered.

Today, new fossils and modern techniques are updating the story of snakes. Starting about 125 million years ago, snakes used their flexible body plans to diversify like crazy, conquering regions that now make up six continents, plus the Indian and Pacific Oceans — and Tollis would not be surprised to find snake fossils in once-balmy Antarctica, either.

There are serpents slithering across the land, burrowing into the soil, swimming in the sea and gliding between trees, even catching rides on trains and, yes, planes. There are itty-bitty threadsnakes just a few inches long and thin as spaghetti, and there are pythons that exceed 20 feet. There are snakes that chase their prey and snakes that lie in wait to ambush it, snakes that strangle their meals and others that immobilize their dinner with venom. Snakes that lay eggs, snakes that bear live young, snakes that can reproduce without males.

It's an impressive smorgasbord of abilities for what is, essentially, a freaky offshoot on the lizard family tree. Serpents are basically predatory tubes, Tollis notes. They can't walk or chew their food. These seem like seriously limiting factors.

"Despite that, snakes are some of the most successful animals," marvels Tollis, who coauthored an overview of early snake and lizard evolution in the 2025 Annual Review of Ecology, Evolution, and Systematics. "They definitely have superpowers that we would normally associate with the fantastic."

By sea, by land, or below?

There are more than 4,000 described living species of snakes, accounting for about one-third of the larger lizard group, and probably hundreds more awaiting official discovery, says Alex Pyron, an evolutionary biologist at George Washington University in Washington, DC. Scientists estimate that the ancestors of this wildly diverse group emerged around 160 million years ago, but they haven't figured out what the first snakes were like — land snakes, sea snakes, perhaps underground snakes?

These mysterious, ancestral snakes should sit at the very base of the snake family tree, but their fossils haven't been found. The oldest snake fossils known come from a variety of environments, making it hard to determine which kind of habitat snakes wriggled out of, says Tiago Simões, a coauthor on the Annual Review  paper and an evolutionary biologist at Princeton University in New Jersey.

One longstanding hypothesis is that snakes got their start underground. The original idea was based, in part, on the barely-there eyes of the blind snakes that are the lowest branch on the family tree of living snakes. But blind snakes are quite specialized for the anthills and termite mounds they inhabit, says Catie Strong, a vertebrate paleontologist and graduate student at the Harvard Museum of Comparative Zoology in Cambridge, Massachusetts.

They have weird, alien-looking skulls fit for their subterranean environment and insectivore diet. For example, Strong says, a "pronounced underbite" helps keep dirt out of their mouths. While training with vertebrate paleontologist and evolutionary biologist Michael Caldwell at the University of Alberta in Edmonton, Canada, Strong concluded, as have other researchers, that these hyperspecialized critters can't correspond to the root of the snake family tree.

In the late 20th century, evidence supporting a possible marine origin floated up. Scientists described early snakes that lived nearly 100 million years ago in the Middle East, when that land was underwater. Caldwell and colleagues also linked the snake clan to mosasaurs, extinct aquatic reptiles, raising the possibility that snakes emerged in the water. But favor for that hypothesis has sunk: There are other snakes that predate those aquatic snakes and were clearly terrestrial, says Simões. So the current consensus is that the Middle Eastern swimmers didn’t spring from the water but dived into it from land.

Modern-day Patagonia has yielded a trove of additional snake fossils, such as Najash rionegrina, dated to about 95 million years ago, and Dinilysia patagonica, from about 80 million years ago, when that environment was desertlike. But were these South American serpents on the ground, or under it? Dinilysia probably lived aboveground, but the situation with Najash is trickier, says Simões.

Najash has skull and spinal features that, to its discoverers, suggested it spent at least some time underground. But both of these Patagonia species were "big-bodied snakes," adds Caldwell, similar to modern-day pythons. Like pythons, they might have hid out underground, but hunted on the surface, he speculates.

Additional evidence for a mixed dry land/underground origin comes from predictions about early snakes' brains. Scientists used 3D X-ray imaging to analyze the braincase — the part of the skull protecting the brain — of nearly 60 snakes and lizards, plus a few snake fossils. From those inner contours, they could infer the shape of the brain. The researchers identified burrower brain anatomy: Diggers usually possess, for example, a small, flattened, triangular cerebellum, a brain section involved in movement. When the researchers used their data to predict the ancestral snake brain shape, they wound up with some burrower-like features, including that little cerebellum, but other features inconsistent with underground living.

Bringing all the evidence together, Strong subscribes to a theory that snakes evolved on land, maybe in a sandy environment like the one Dinilysia and Najash inhabited. This, she suspects, also happened to set them up to navigate underground on occasion.

A better way to slither

Another major event in snake evolution was, of course, the shedding of their legs. This is not as innovative as it might seem; among lizard-kind, several long, skinny groups have kicked their legs to the curb. When one is crawling underground or moving through grass, limbs are literally "a drag," says Daniela Garcia Cobos, an evolutionary biologist and graduate student at the American Museum of Natural History in New York City. Snakes do, however, seem to have been among the first lizards to master this streamlined shape in a variety of different types of habitats, which might underlie their success with it.

Pyron estimates this change happened between 150 million and 125 million years ago, but scientists haven’t been able to pin down exactly when or where. The known fossil snakes had hind limbs but not forelimbs, though Dinilysia’s status is uncertain because there hasn't been good evidence of pelvic region preservation in those fossils. At some earlier point, there must have been a four-legged snake ancestor, but this missing link has been elusive. One candidate was reported in 2015, but Caldwell and collaborators showed it was just a lizard.

Then came Breugnathair elgolensis, a four-legged Jurassic fossil found in Scotland and described in Nature in 2025. "If you saw it in the street, walking across the road, you’d think it was just an iguana or ordinary lizard," says Susan E. Evans, a paleontologist at University College London, who described the specimen with colleagues.

But B. elgolensis's jaw does have some snaky features, like the shape of its teeth. Caldwell, who wasn't part of the team that described it, thinks it's a snake. "It's got all the right skull features," he says.

Evans isn't so certain, an opinion evident in the name she chose: Breugnathair derives from Gaelic for "false snake." When Evans and colleagues tried to place it in the reptile family tree, the results were wishy-washy. It might be a snake ancestor, she concedes, or it could be a lizard that independently evolved snakelike features but left no living descendants.

Heady changes

What distinguished snakes from all other legless lizards were the other changes they made, says Pyron. To investigate further innovations, Pyron and collaborators embarked on a massive reptile census, which they published in Science in 2024. They measured the skulls of thousands of snakes and lizards. They examined the stomach contents of museum specimens and pored over written dietary records. They amassed genetic data — not the whole genome, but 5,400 specific genes — from more than 1,000 snake and lizard species.

When they lined up those features, snakes stood out. About 125 million years ago, the group underwent sudden and significant changes to their skulls, diets and spines that would position them to diversify and spread.

Snakes' biggest claim to evolutionary fame is their weirdly flexible craniums, made of bony pieces connected by soft tissue; Caldwell thinks this key alteration might have happened even before they gave up their legs. En route to those piecework noggins, snakes first changed up their braincase. In most lizards, this looks like a sandwich: bone on top, bone on the bottom, brain within and open on the sides. But in snakes, it's more like a wrap, a bony tube that's only open toward the face and spine. Protecting the brain that way meant snakes were free to let the rest of the skull's bones move about. And boy, did they.

Those skull changes enabled new diets with the evolution of the serpentine jaw. While jaw anatomy varies within the group, in many snakes, the lower and upper parts are connected by stretchy ligaments, enabling a wide gape. The two sides of the lower jaw can splay apart, further expanding the snake's maw. The palate at the top of the mouth has right and left parts that move independently to convey food throatward. That's how a python can swallow a pig. Indeed, the Science team found that snakes, as a clan, can eat pretty much anything that moves. There are snakes that nosh on gooey slugs and armored snails, slippery eels and even other serpents.

And around the same time, snakes grew longer, adding hundreds of vertebrae between their necks and nether regions. "Being elongate allows you to locomote more quickly and efficiently," says Caldwell. Extra belly flesh supplies more surface area to push along the ground or climb tree trunks. For aquatic snakes, increased body length enables more efficient weaving back and forth.

In sum, these changes to body, head and diet meant the evolving serpents were flexible not just in form, but also in lifestyle. Snakes adapt rapidly to new environments, says Frank Burbrink, curator of herpetology at the American Museum of Natural History and a coauthor of the Annual Review  article. In other words, these evolutionary superstars were primed to make the most of any habitat they slithered into.

Making up for absent fossils

The fragmented skulls and the body length that were so beneficial for snakes' spread create a headache for paleontologists: Dead snakes go to pieces, making complete fossils scarce and leaving many questions unanswered. For example, researchers know serpents are related to groups containing iguanas and Komodo dragons, as well as possibly those mosasaurs, but it's not certain which are their closest cousins. Knowing that would help to predict what snake ancestors should look like, says Evans.

When fossils falter, genetics can come to the rescue. The more dissimilar the genes from different animals, the longer it's been since they went their separate ways as species. Already, genetic analyses have forced a reshuffling of the lizard family tree; trees based on body shape alone turned out to be "totally wrong," says Pyron.

Genes have also illuminated how snake bodies build some of their special features. The lack of legs is linked to lost function in a limb-promoting sequence called ZRS. And scientists recently reported that snakes lack the gene encoding the "hunger hormone" ghrelin. This might make it easier for them to endure long fasts; some snakes can go for a year or more between repasts.

Burbrink, Pyron and Simões are now sequencing whole genomes of more than 100 snakes and lizards, which will double the number of high-quality genomes available. With that plus additional data on living and fossil reptiles, they expect to build better family trees and further investigate the genes behind a snake's sinuous shape.

Still, Evans says, scientists really need more fossils to fill in the twists and turns in the serpents’ tale.

As paleontologists keep digging, Burbrink counsels us to take a moment to marvel the next time we come across a garter snake or other modern wriggler: "You're looking at the culmination of more than 100 million years of evolution."

This article originally appeared in Knowable Magazine, a nonprofit publication dedicated to making scientific knowledge accessible to all. Sign up for Knowable Magazine’ snewsletter.

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Cannibalism might seem like a rare and unnatural occurrence, but the behavior has arisen in several snake lineages throughout evolutionary history, often triggered by environmental stressors, scientists theorize.

When researchers reviewed 500 reports of cannibalistic behavior across snake species, they found that cannibalism has evolved independently at least 11 times, according to a study published Nov. 2, 2025, in the journal Biological Reviews.

These cannibalistic behaviors occur in diverse contexts, but overall, cannibalism is common and seems to emerge repeatedly because it's beneficial to snakes in situations where they need to make opportunistic dietary choices, the researchers suggest.

"For us humans, we don't think of cannibalism as something common –– it's something weird and disgusting," Bruna Falcão, lead author of the study and a graduate student in biology at the University of São Paulo, told Live Science. "But for snakes, it's good for them; it's good for their ecological fitness. … It's strategic."

Evolutionary advantages of cannibalism

Some of the best-known examples of cannibalism in nature are seen in spiders and praying mantises during mating, as it may be beneficial for females to eat their mates. "Cannibalism is widespread throughout the animal kingdom," Xavier Glaudas, a biologist and National Geographic Explorer who was not involved with the study, told Live Science.

Although scientists previously considered the behavior maladaptive –– meaning it's not beneficial for a species overall –– more and more studies reporting cannibalism in animals hypothesize reasons for the evolution of the behavior. For example, it could help parents control brood size, or it might arise as a response to limited resource availability, a form of population control, or an opportunistic predation choice.

Cannibalistic behavior in snakes has typically been recounted in brief and isolated reports, Glaudas said. For example, his research team described male Montpellier snakes (Malpolon monspessulanus) feeding on female snakes in France — a behavior thought to be driven by limited food resources, especially during times of scarcity outside the mating season. (It would be considered unusual for males to eat females during the mating season, as this would reduce mating opportunities.)

In addition to being widespread in snakes, cannibalism has evolved independently across different snake lineages and regions, according to the study, which combined numerous reports to explain the behavior.

The research team gathered 503 cases of reported cannibalism across 207 snake species. The reports spanned a wide range of snake groups, as well as all continents where snakes live, including reports of snakes both in the wild and in captivity.

"None of us expected that … snakes could be so cannibalistic, and no one was talking about it," Falcão said. "The more we were searching, the more cases we found."

Cannibalism was most common in the Colubridae, Viperidae and Elapidae families, the team found. Colubridae is the biggest family of snakes and made up 29% of all reports. Because this family is not typically known to prey on snakes, however, the authors proposed that most cases of cannibalism in this group may be connected to stressors such as a lack of other food sources. Members of the Viperidae family, which includes vipers, made up 21% of all cannibalism reports. But these were mostly cases in captivity, the researchers noted, so captivity-related stressors, like confinement to small spaces with limited food, may have resulted in cannibalism.

Elapidae, the snake family that includes cobras, accounted for about 19% of the cannibalism reports. This wasn't very surprising, the researchers said, because cobras are known to prey on other snakes in the wild.

Almost half of the cannibal snake species have generalist diets, according to the study, and the researchers linked this dietary flexibility to cannibalistic behavior when necessary. However, Glaudas suggested this connection may not be clear, since the researchers defined only 47.7% of the cannibal snake species as generalist; evidence for the relationship would be stronger if the percentage were higher, he said.

"In regard to the idea that cannibalism could be more common in generalist species, I am a bit more skeptical about the data presented," Glaudas said.

Cannibalistic behavior does seem to be correlated with jaw structure, so whether a snake has jaws that can open wide enough to consume another snake is a key factor; there were no reports of cannibalism in snake species without this ability.

When the researchers analyzed cannibalistic behavior across snakes' evolutionary history, they concluded that the behavior evolved independently at least 11 times throughout the snake evolutionary tree.

Because most reports of cannibalism in snakes are anecdotal, Glaudas said, the study provides a useful overview. This is a "welcome study that allows us to get a better understanding of the correlates of cannibalism in snakes," Glaudas said.

Snakes form a highly successful branch of the evolutionary tree. They are found on all continents except Antarctica and have adapted to most ecological niches, the study authors noted. Because cannibalistic behavior appears in many different types of snakes throughout the world, Falcão said, it might reflect their ability to adapt opportunistically to their circumstances. "It's really surprising for [cannibalism] to evolve independently 11 times in snake lineages," she noted.

The review could not encapsulate all reports of cannibalism in snakes — many are in less-accessible, older books and archives — so there's likely much more to discover on the topic, Falcão said.

In 2024, scientists announced the discovery of a newfound anaconda species in the Ecuadorian Amazon. Now, in a new nature series, filmmakers have released nail-biting, never-before-seen footage of the moment they encountered the snake in the wild.

The footage transports viewers to the Baihuaeri Waorani Territory in the Amazon rainforest, where researchers were sampling anacondas in 2022 for a snake genetics study. In the video, venom expert Bryan Fry and actor Will Smith travel by boat with Indigenous Waorani guides along the banks of a murky river. In a small clearing, the group spots a gigantic anaconda, which the guides manage to immobilize so that Fry and Smith can take a piece of its scales.

The anaconda in the footage — which features in an episode of National Geographic's upcoming "Pole to Pole with Will Smith" docuseries — is a female measuring 16 to 17 feet (4.9 to 5.2 meters) long, Fry estimates in the show. There is a danger she might bite, says one of the Waorani guides who helps pin down the snake, even if green anacondas aren't venomous. Anacondas are constrictors, meaning they kill prey by wrapping their bodies tightly around it, suffocating the animal before swallowing it whole.

The scale sample and others taken in 2022 revealed that green anacondas, which were previously thought to all belong to one species, actually form two separate species: Eunectes murinus, the already-identified southern green anaconda, and Eunectes akayima, the newfound northern green anaconda.

"Finding a new species is so often not a case of actively searching but rather having rigorous scientific process in place so that serendipity can strike," Fry, who is a professor of toxicology at The University of Queensland in Australia, told Live Science in an email. "The research into the genetics of the iconic green anaconda is textbook in this regard."

Genetic analyses indicate that E. murinus and E. akayima diverged 10 million years ago. Since then, northern and southern green anacondas have accumulated thousands of genetic differences adding up to a whopping 5.5% of their total DNA. By comparison, the level of mismatch between human and ape DNA is about 2%.

As its name suggests, the northern green anaconda inhabits the Amazon's northern basin, which includes parts of Ecuador, Colombia, Venezuela, Trinidad, Guyana, Suriname and French Guiana. The southern green anaconda, on the other hand, is found in the Amazon's southern basin, which stretches across Brazil from Peru and Bolivia to French Guiana. Both species live in wetlands and rivers, spending most of their time submerged in water. Their olive-green coloring blends into their surroundings, which helps green anacondas ambush large prey such as capybaras (Hydrochoerus hydrochaeris), caimans and deer.

Green anacondas are the world's heaviest snakes, with some specimens weighing more than 550 pounds (250 kilograms) and exceeding 12 inches (30 centimeters) in girth. Female northern green anacondas grow the largest and heaviest, while their male counterparts have more slender bodies. This means female and male northern green anacondas hunt different prey and occupy different positions in the food chain, Fry said.

"Females and males live in the same environment, but they feed differently," he said.

The northern green anaconda is the fifth described anaconda species in the world — and there may be more hiding out there, Fry told Live Science. "Despite anacondas having a state of fame exceeding that of any other reptile, they are really poorly known," he said.

Knowledge of the northern green anaconda's existence is important in and of itself, but the difference in male and female diets could also give clues about the health of the ecosystem — and the people who live in it, Fry said. Female northern green anacondas feed lower in the food chain than males do, preying on animals such as deer. The males eat more predatory fish and caimans, meaning they accumulate more toxins leftover in the environment from events like oil spills than females do, he said.

Male northern green anacondas' diet resembles that of humans living in the Amazon. Therefore, the concentration of toxins in these anacondas provides an estimate of the pollution that people are exposed to — and that pollution is high, Fry said.

"The concentrations of the heavy metals cadmium and lead, potent endocrine disruptors that are the signature of oil spills, were over 1000 percent higher in males than females," he said. "That is not a subtle difference. That is a warning flare."

In light of these findings, Fry is developing a wild food guide for the Waorani. "Recommendations will include pregnant women and young children avoiding top-level predators likely to carry higher contaminant loads, such as arapaima and arowana [two types of predatory freshwater fish]," he said.

"Pole to Pole with Will Smith" premieres Jan. 13 on National Geographic, and Jan. 14 on Disney+ and Hulu.

How to watch "Pole to Pole with Will Smith" in the U.S.

"Pole to Pole with Will Smith" premieres in the U.S. on National Geographic and will be available to stream on Disney+.

The first two episodes will air from 9 p.m. ET / 6 p.m. PT on Tuesday Jan. 13 on TV. Then, on Jan. 14, all seven episodes will be available to stream in one go on Disney+.

How to watch "Pole to Pole with Will Smith" in the U.K.

"Pole to Pole with Will Smith" will also air on the National Geographic TV channel and the Disney+ streaming platform in the U.K.

The premiere is a day later than the U.S. release, landing on Jan. 14 at 8 p.m. GMT. All seven episodes will be available to stream on Disney+ for U.K. subscribers from Jan. 14.

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Anacondas have been giant for millions of years, a new study finds.

The enormous snakes' average body size has remained constant since they first appeared in the fossil record about 12.4 million years ago, during the Middle Miocene (16 million to 11.6 million years ago), researchers revealed in a new study published Monday (Dec. 1) in the Journal of Vertebrate Paleontology.

During the Middle and Upper Miocene (12.4 million to 5.3 million years ago), warm temperatures, expansive wetlands and abundant food enabled many animal species to grow much larger than their modern relatives. But few of these giant animals have survived to the present day.

"Other species like giant crocodiles and giant turtles have gone extinct since the Miocene, probably due to cooling global temperatures and shrinking habitats," study co-author Andrés Alfonso-Rojas, a vertebrate paleontologist at the University of Cambridge, said in a statement. "But the giant anacondas have survived — they are super-resilient."

Anacondas make up a group of constricting snakes that today includes the heaviest snake species in the world. Modern anacondas average 13 to 16 feet (4 to 5 meters) in length, though the largest can reach up to 23 feet (7 m). Scientists weren't sure whether anacondas had been even larger during the Miocene, or whether they had been the same size and retained their massive size into the present day.

To estimate how big ancient anacondas might have been, Alfonso-Rojas and his colleagues measured 183 fossilized anaconda vertebrae from at least 32 individual snakes collected in Venezuela. They also used a technique called ancestral state reconstruction to predict the body lengths of ancient anacondas from characteristics of related snakes.

Based on these calculations, the team found that anacondas averaged about 17 feet (5.2 m) long when they first appeared during the Miocene 12 million years ago — roughly the same length as modern anacondas.

"This is a surprising result because we expected to find the ancient anacondas were seven or eight meters [23 to 26 feet] long," Alfonso-Rojas said in the statement. "But we don't have any evidence of a larger snake from the Miocene when global temperatures were warmer."

It's still unclear why anacondas have not become smaller over time.

Although warm weather and abundant wetlands may have enabled anacondas to reach their giant size early in their evolutionary history, cooler temperatures and shrinking ranges haven't forced the snakes to get smaller to adapt. That could suggest that these weren't the primary factors keeping the snakes large in the intervening millennia, the researchers wrote in the study.

Predator-prey interactions likely didn't play a major role in maintaining the snakes' body size, either, the researchers said. A lack of competition for food could have helped the snakes grow large in the first place. But they didn't get smaller as other predators moved into South America during the Pliocene (5.3 million to 2.6 million years ago) and the Pleistocene (2.6 million to 11,700 years ago), suggesting that food availability isn't a big factor in anacondas' giant size.

Snake quiz: How much do you know about the slithering reptiles?

More than 300,000 snakebite cases occur in Africa annually, resulting in at least 7,000 deaths, as well as numerous amputations and injuries. Now, scientists have invented a new nanobody-based antivenom that shows promise against 17 dangerous African snake species.

Until now, the mainstays of treatment have been antivenoms created by exposing horses to particular venoms and then isolating protective antibodies from the animals' blood. These traditional antivenoms can occasionally cause allergic reactions in patients, and they are effective against only one or a few of related snake species.

Now, in a study published in October in the journal Nature, scientists report creating an antivenom that targets most of Africa's deadliest elapids, meaning cobras, mambas, and the rinkhals, also called ring-necked spitting cobras. Instead of horse serum, the antivenom uses eight engineered nanobodies that are essentially tiny antibody fragments designed to block key toxins in the snakes' venoms.

Juan Calvete, director of the Evolutionary and Translational Venomics Laboratory at the Biomedicine Institute of Valencia, who was not involved in the study, said the new nanobody-based antivenom is "a remarkable advance in the development of synthetic antivenoms." However, he noted that in its current form, the antivenom may be expensive to make, and thus challenging to use in poorer regions.

To create the new antivenom, researchers exposed an alpaca and a llama to venoms from 18 African snakes, including cobras, mambas, and the rinkhals. These snakes' venoms are potent and can cause serious problems, such as paralysis and tissue damage, and they also contain a diverse range of toxins.

The llama and alpaca exposed to the venoms produced special, tiny antibodies, known as nanobodies. The compact size of these nanobodies enables them to diffuse quickly through tissues and bind toxins at hard-to-reach sites in the body, the study authors noted.

The researchers collected the animals' blood and used a technique to find nanobodies that stick well to various venom toxins. The nanobodies that latched on most effectively were then made in the lab and tested for their ability to block the venoms' effects. Finally, eight of these engineered nanobodies were combined into a powerful mix to create the new antivenom.

In lab tests in mice, this nanobody serum prevented death from 17 of the 18 target snake venoms; the venom of the eastern green mamba (Dendroaspis angusticeps) was the only one not fully neutralized. Further analyses suggested that the antivenom neutralized seven toxin families found within the venoms and that it reduced tissue damage from venoms known to kill cells.

The antivenom outperformed a commonly used antivenom designed to target multiple toxins: Mice given the nanobody mix survived multiple venoms with fewer symptoms than did mice treated with the traditional horse-antibody-based serum.

"The main advance of our work is showing that an effective recombinant antivenom can be made with a surprisingly small number of nanobodies that outperform existing ones," senior study author Andreas Hougaard Laustsen-Kiel, a biotechnologist at the Technical University of Denmark, told Live Science in an email. The new antivenom was better at preventing both lethal effects and tissue damage, and it could theoretically be "produced at large scale in bioreactors, independent of snakes and horses," he said.

The next steps include testing the antivenom's effects in larger animals to estimate what dose a human might need and optimize the process to scale up production. "We are also testing some of these nanobodies, and new ones, against Asian cobra venoms to develop cocktails with broader species coverage and geographical relevance," Laustsen-Kiel said.

The idea of a broad-spectrum — or even "universal" — antivenom has recently gained traction. A notable 2025 study published in the journal Cell used human antibodies from a snakebite survivor to protect mice from multiple cobra and mamba venoms. Yet practical and economic barriers remain to developing such an antivenom and manufacturing it affordably and scalably.

Calvete called the new nanobody venom a significant advance, but he cautioned that dosing requirements in humans might complicate things. "A therapeutic dose to treat envenomings from all target snakes could require up to 50 grams of nanobodies," he suggested. (That said, tests to officially determine human dosing have yet to be conducted.)

He added that improving the pharmacokinetics of the antivenom — that is, how the treatment interacts with the human body — would likely increase production costs beyond what was seen in this proof-of-concept study. "The most powerful of all the 'omics' — economics — may once again represent an insurmountable obstacle to fighting the most neglected of tropical diseases," he concluded.

In theory, the new nanobody mixture could represent a promising step toward safer, scalable snakebite therapies, but further testing, manufacturing optimization, and regulatory validation will be crucial to getting it into human patients.

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

Scientists finally know how venomous snakes sink their teeth into prey thanks to a series of high-speed videos.

In a new study, published Thursday (Oct. 23) in the Journal of Experimental Biology, scientists recorded various species of snakes striking fake prey, capturing footage from multiple angles and in high definition. The videos revealed three different ways that the snakes take down their dinners.

Scientists have captured the moment when a venomous snake lunges for its meal in photographs and video since the early 1950s. But the strikes happen so quickly — in as little as 0.1 seconds — that older cameras weren't fast enough to catch all the details. More recent field recordings of snake strikes, meanwhile, have often been limited by low resolution and dim lighting, researchers wrote in the new study.

To better understand how different types of snakes attack their food, researchers traveled to Venomworld in Paris, an animal facility where study co-author Remi Ksas and colleagues regularly extract venom from snakes and scorpions for medical and pharmaceutical work. There, they crafted fake prey from a muscle-like medical gel and dangled it in front of 36 species of venomous snakes while filming with multiple high-speed cameras.

While tempting the snakes to strike, "I flinched a couple of times," study co-author Silke Cleuren, a biologist at Monash University in Australia, said in a statement.

After recording more than 100 high-speed videos of 36 different snake species striking at the fake prey, the scientists spotted patterns in how these reptiles attack. The footage revealed that most vipers bit their target within 0.1 seconds of lunging — faster than most mammals' startle response, meaning their prey would be unlikely to escape. While some elapids — the family that includes the rough-scaled death adder (Acanthophis rugosus) and the Cape coral snake (Aspidelaps lubricus) — were just as fast as viperids, others took more than 0.3 seconds to reach their prey.

Different families of snakes injected their venom in different ways, too. Viperids struck quickly from a coiled position but sometimes didn't get a good angle on their bites. If that happened, the viper would pull a fang out of its prey and reinsert it in a more favorable position before injecting its venom.

Elapids took a sneakier approach, slithering up close to their prey to reduce the distance they had to lunge. They then slightly loosened their jaws and bit down again several times, "likely to prolong the venom flow into their prey," the researchers wrote in the study.

The team also observed two snakes from the colubrid family, the mangrove snake (Boiga dendrophila) and Fischer's tree snake (Toxicodryas pulverulenta). These "rear-fanged" snakes inject venom through teeth at the back of their upper jaw. When T. pulverulenta bit the fake prey, it dragged its fangs back and forth across the gel, creating crescent-shaped wounds that may help it deliver as much venom as possible.

Future studies could determine if the size of the prey has any effect on the snakes' attack, the researchers wrote in the study.

When Jacob Glanville first spoke to Tim Friede, he said, "I'd love to get my hands on some of your blood."

As CEO of the biotech company Centivax, Glanville was developing a universal snakebite treatment. And Friede is a self-taught herpetologist with hyperimmunity to some of the world's deadliest snake toxins.

Over the past two decades, Friede has had over 800 snakebites and "self-immunizations" with the venom of cobras, taipans, black mambas, rattlers and more. By carefully increasing the doses of diluted venom, he "trained" his immune system to produce antibodies that worked against a broad variety of snake venom toxins.

What Glanville needed for his "universal" antivenom were several antibodies, each of which could neutralize many different versions of a toxin. That's no small task. A snake venom is a mixture of up to 70 toxins. And different snakes can produce different combinations, variants and amounts of these toxins, even in the same species across and within geographic regions. Even small chemical variations from one toxin to the next could result in a very different reaction to a bite, making an antivenom effective against one snakebite but ineffective against another.

But Glanville suspected it was still possible to achieve his goal, because structurally, all venom toxins are variations of around 10 protein classes. That suggests that the key sites where these proteins bind to human cells could be similar across many venoms.

If researchers could find antibodies that latch onto these common binding sites,"we could make a cocktail that could be a universal antivenom," Glanville said.

He was hoping that the antibodies in Friede's blood might work against some of those similar sites. With a 40-milliliter blood sample from Friede, Glanville worked with biochemist Peter Kwong and others from the National Institutes of Health and Columbia University to create a "broad-spectrum" antivenom. In 2025, Glanville, Kwong and colleagues reported that, in mice, a mix of three agents including some derived from antibodies in Friede's blood provided broad protection against the venom of 19 snakes of the elapid family, which has about 300 species, including various cobras, mambas, taipans and kraits.

Glanville thinks his research shows that a universal antivenom is within reach. But other experts are skeptical of the need and practicality of this approach. What's needed, they say, is not a "universal antivenom." They'd rather see a suite of several antivenoms, with each one tailored to the snakes in a given geographic region and able to be made cheaply and quickly.

A toxic threat

Up to 138,000 people die of bites from venomous snakes every year, mostly in Africa, Asia and Latin America, according to the World Health Organization. These numbers may be an underestimate, however, because people who are bitten may not always seek medical treatment.

Plus, getting the right antivenom quickly is a challenge. People may not always know which snake has bitten them, as there are about 600 species of venomous snakes and often multiple venomous snake species in a given region..

Generally, the toxins in snake venom fall into three categories: neurotoxins, which damage the nervous system; hemotoxins, which disrupt blood flow and clotting; and cytotoxins, which damage cells and tissue.

Most elapids rely on neurotoxins. Among the deadliest types are three-finger toxins (3FTXs), so called because of the characteristic finger-like loops in these protein structures. The 3FTX family includes long- and short-chain neurotoxins (LNX and SNX), which are the most dangerous because they often bind swiftly and irreversibly to the receptors on muscle nerve cells, preventing them from firing.

If not counteracted, 3FTXs cause rapid muscle paralysis and death.

Developing a universal antivenom

To develop their new antivenom mixture, Glanville's team isolated DNA from Friede's blood and created a library of the antibodies in it that counteracted snake venom toxins. From these, they isolated those that neutralized many of the most dangerous ones.

"The way antivenoms work is, if you disable one [toxin], it neutralizes the whole thing," said Kartik Sunagar, an evolutionary geneticist who leads the Indian Institute of Science's Evolutionary Venomics Lab and is working to develop antivenoms for snakes found in specific regions in India. "This is how you can achieve broad neutralization, as many of these toxins are shared across species."

Glanville and colleagues found that an antibody called LNX-D09 was effective against LNXs, while another, SNX-B03, worked against SNXs. They combined these with a drug called varespladib, which was previously shown to neutralize another type of snake venom toxin, called phospholipase A2 (PLA2), which breaks down cell membranes, causing tissue death, inflammation, hemorrhage, or swelling . This cocktail protected mice from 19 venomous snake species — full protection against 13 species, and for the remaining six, it reduced the severity of symptoms. Their paper was published earlier this year in the journal Cell.

A daunting task

But the complexity of snake venoms makes developing a one-size-fits-all solution extremely daunting.

"A snakebite is not just one disease…[and] behind each snakebite is a different venom composition, The toxins important in African snakes may not even exist in any snake venom in the Americas," said Andreas Hougaard Laustsen-Kiel, a biotechnologist at the Technical University of Denmark who is working to develop broad-spectrum snakebite treatments. "The toxins important in African snakes may not even exist in any snake venom in the Americas."

Laustsen-Kiel doesn't think a universal antidote to snake venom is possible — or even necessary. "You don't make a drug where you take insulin, Alzheimer medicine, cancer medicine, a medicine against bad breath, make it into one pill, and say, hey, [if you] suffer from one of these things, here, just take our multi-drug," Laustsen-Kiel told Live Science.

He also cautioned against hyping the idea that a "universal" antivenom is near. Glanville's team's new antivenom cocktail is effective against snakes from many regions, but it works only for the venoms in the study.

"To a non-expert it might look like very broad neutralization, but all the species picked have venoms that are very similar," Laustsen-Kiel said. But the snakes highlighted in the study often have close cousins in the same regions that make venom that differs from those targeted in the new mixture, so it isn't likely to work on their venoms, he added.

Still, he said, Glanville and team's work is significant because it validates an approach that has been around for a decade. "If you go one by one, make good, broadly neutralizing antibodies, and make cocktails [of those], that is likely a good strategy for making better antivenoms."

Instead of trying to make a universal antivenom, a better approach would be to mix-and match a panel of broadly neutralizing antibodies specific to each geography, he said. This would mean targeting the venoms of snake species found in a given area, not the world over.

The century-old technology behind snake antivenom production

But there's another barrier to an ideal antivenom: Production still relies on the 125-year-old technology of injecting animals like horses or sheep with venom and using their antibodies to create antidotes for humans. There are many drawbacks to this approach. First, most snake species don't have specific antivenoms, and even if they do, their effectiveness can vary because of venom differences. Plus, nonhuman antibodies risk causing allergic reactions like anaphylaxis and serum sickness in some users.

What the field needs, Laustsen-Kiel wrote in 2024, is a way to quickly and efficiently produce human monoclonal antibodies (mAbs) — lab-made antibodies designed specifically for the human immune system — that work against many variations of the same class of toxin.

We may be closer to that goal than to a universal antivenom. In February 2024, Sunagar and colleagues reported a broadly neutralizing human mAb against a diverse array of LNXs from elapids. After testing over 50 billion synthetic human antibodies, they zeroed in on one that did the job. Their study presented a framework for developing more such antivenom treatments.

The secret to such broad neutralization, Sunagar told Live Science, is that if you disable one key component in snake venom, it neutralizes the venom entirely. So you would only need to find one specific antibody that could be effective against many venoms with similar toxins.

Their synthetic antibody neutralized whole venoms of the king cobra (Ophiophagus hannah) in the Western Ghats in India, the monocled cobra (Naja kaouthia) in eastern India, the many-banded krait (Bungarus multicinctus) in Southeast Asia, and the black mamba (Dendroaspis polylepis) in sub-Saharan Africa.

"Achieving broad neutralization is not a challenge anymore," Sunagar told Live Science. "The only challenge would be to mass-produce these antibodies and make them available to snake projects."

That's because the more components an antivenom treatment has, the more expensive it becomes, making it economically infeasible to produce and distribute in developing countries, which bear the brunt of snakebites, he added.

While Glanville believes a universal antivenom is possible, his antivenom cocktail has yet to be tested in humans. His company is in talks with a veterinary group in Australia to try out the cocktail in pet dogs with snakebites. They are also looking at creating a similar mixture of broadly neutralizing antibodies for the viper family.

On the other side of the world, Sunagar's lab is working on an antibody against vipers in India. His idea of a universal antivenom is not a single product.

"Theoretically, it's possible to make such an antivenom, but I don't think that's necessarily the best solution," he said. Rather, he sees a combination of two or three products for different regions that would neutralize a much broader spectrum of snake venoms than is currently available.

Meanwhile, Glanville's team is now developing an antivenom to counteract bites from the other major venomous snake family, the vipers.

“We're running the same game plan that we did on the elapids...[and] building a second cocktail,” Glanville said.

The fossilized skeleton of a Jurassic reptile that appears to be part lizard, part snake, has been unearthed on Scotland's Isle of Skye.

This mysterious lizard had hooked, snake-like teeth for hunting down prey 167 million years ago, a new study has found.

The newly discovered species is named Breugnathair elgolensis, which means "false snake of Elgol," honoring the creature's confusing anatomy and the Elgol area of southern Skye, where the fossil was found, according to the study published Wednesday (Oct.1) in the journal Nature.

B. elgolensis was only about 16 inches (41 centimeters) long, but that still made it one of the largest lizards in its ecosystem, according to a statement released by the researchers. Scientists suspect that it hunted smaller lizards, early mammals and even young dinosaurs, such as small herbivorous heterodontosaurids and predatory bird-like paravians.

It had a snake-like jaw and curved teeth similar to a modern python, but its body was short, with fully formed limbs like a lizard. B. elgolensis also had gecko-like features on some of its bones, including the back of its skull. Researchers are still deciphering B. elgolensis' evolutionary history, but its discovery could change the way they look at early snake evolution.

Related: Night lizards survived dinosaur-killing asteroid strike, despite being close enough to see it happen

Scientists currently have a scattered understanding of early lizard and snake evolution. Both animals belong to a group called Squamata, which emerged about 190 million years ago. There's some overlap between members of the group, but lizards came first and generally have four limbs, while snakes are limbless.

"The Jurassic fossil deposits on the Isle of Skye are of world importance for our understanding of the early evolution of many living groups, including lizards, which were beginning their diversification at around this time," study co-lead author Susan Evans, a professor of vertebrate morphology and paleontology at the University College London, said in the statement.

Study co-author Stig Walsh, a senior curator of vertebrate paleobiology at the National Museums Scotland, first uncovered the B. elgolensis fossil in 2015. The team has since spent nearly a decade preparing and studying the specimen, which has included subjecting it to high-powered X-rays and detailed computed tomography (CT) imaging scans.

The researchers determined that B. elgolensis belonged to a Squamata sub-group called Parviraptoridae, which was previously only known from fragments of other fossils. While snake-like bones had been found in close proximity to gecko-like bones, some scientists had assumed they came from two separate animals. The new fossil confirms that one species did indeed have both features, according to the statement.

"I first described parviraptorids some 30 years ago based on more fragmentary material, so it's a bit like finding the top of the jigsaw box many years after you puzzled out the original picture from a handful of pieces," Evans said. "The mosaic of primitive and specialized features we find in parviraptorids, as demonstrated by this new specimen, is an important reminder that evolutionary paths can be unpredictable."

The researchers still aren't sure whether snakes evolved from species like B. elgolensis or whether snakes independently evolved similar mouth parts. It's also possible that B. elgolensis is a stem lineage within Squamata, helping to give rise to all lizards and snakes.

"This fossil gets us quite far, but it doesn't get us all of the way," study lead author Roger Benson, the Macaulay Curator at the American Museum of Natural History's Division of Paleontology, said in the statement. "However, it makes us even more excited about the possibility of figuring out where snakes come from."

A Burmese python in Florida's Big Cypress National Preserve vomited up an entire white-tailed deer after temperatures in South Florida dipped below 50 degrees Fahrenheit (10 degrees Celsius) late last year, well below the cold-blooded creature's comfortable range.

While pythons are known to vomit their meals in cold laboratory settings, scientists had never caught the elusive snakes doing it in the wild — until now. The unusual observation, made in late November 2024, is described in a study published in July in the journal Ecology and Evolution.

"Almost every day is a surprise," Mark Sandfoss, senior author of the study and a biologist at the U.S. Geological Survey (USGS), told Live Science. "Pythons are constantly doing things I never imagined, but this is such a beautiful moment where science and basic principles line up with field observations."

Burmese pythons (Python bivittatus) have been an invasive species in Florida since the late 1970s. Despite this decades-long presence, they are largely understudied, and there are gaps in knowledge about the snakes' biology and how they interact with native species, such as deer.

Deer numbers are declining in the preserve, which is concerning because they form an important part of the diet of local predators, like Florida panthers (Puma concolor coryi). To learn more about how often snakes eat deer and how quickly they digest them, scientists at the preserve spent a year tracking the digestion of several large female pythons — those deemed most likely to eat a deer.

One snake under observation had a large lump in its stomach, indicating that it had eaten something deer-sized. Over the next several days, though, this lump did not appear to get any smaller.

After a cold night, when temperatures dipped to 48.9 F (9.4 C) in the preserve, scientists revisited the snake. They found it lump-free, swimming in the shallow water of a willow swamp near a minimally digested white-tailed deer (Odocoileus virginianus) that it had vomited up.

Related: Scientists discover Burmese pythons have never-before-seen cells that help them digest entire skeletons

"They found her very empty, and they were able to smell a deer not far away and put two and two together," Sandfoss said.

Because snakes are cold-blooded, or ectothermic, they find it difficult to function in the cold. Their biological processes, including digestion, slow down until the temperature warms back up.

If the outdoor temperature gets too cold, a snake's meal can start decomposing in its stomach faster than the snake can digest it, causing bacteria to build up. The snake's response is to vomit to eliminate the bacteria. This can be an energy-intensive activity for an already hungry snake, but the snake in the study survived it.

Because the Burmese python is an invasive species in Florida, the snake's survival has complex implications, Sandfoss said. It missed one of the large meals it takes only a few times a year, so it might lack the energy to reproduce, which could help control the python population. Alternatively, the snake may kill another deer to make up the lost energy, further endangering the deer population native predators rely on.

"Deer in Big Cypress have been declining for several years, and we believe pythons to be a factor in that," lead author Travis Mangione, a biologist at the National Park Service (NPS), told Live Science. "Because this python survived the vomiting event, it will keep eating native wildlife."

Even as scientists work to understand how Burmese pythons' vomiting events affect the local ecosystem, observations of it in the wild hold valuable clues to how far this invasive species can spread within the United States. Temperature is a key limiting factor for the snakes' range, and the coldest temperature they can survive might be the coldest in which they can digest, Sandfoss said.

The new study fits within a larger, not-yet-released research project that's analyzing the full year of python feeding data. The scientists working on the project hope it will shed light on the basic biological process of digestion in Burmese pythons, which is still under-researched.

"Pythons have complicated biology, and we've never really dealt with an animal like this at this scale — this large, invasive ectotherm, terrestrial," Sandfoss said. "We're trying to figure all these things out."

Snake quiz: How much do you know about the slithering reptiles?

Researchers found that specialized cells in Burmese pythons' (Python bivittatus) intestinal lining process calcium from the bones of their meals. This helps explain how these predators digest whole prey.

The team published its findings June 25 in the Journal of Experimental Biology.

Burmese pythons typically dine on birds and small mammals, though they don't need to eat every day. The snakes swallow their prey whole and spend several days digesting their meal before hunting again.

As part of digestion, pythons break down their prey's bones. The bones provide necessary calcium in the snakes' diet — but the pythons can't use all the calcium. "We wanted to identify how they were able to process and limit this huge absorption of calcium through the intestinal wall," study co-author Jehan-Hervé Lignot, a biologist at the University of Montpellier in France, said in a statement.

To examine how the snakes managed their calcium intake, the researchers fed Burmese pythons one of three diets: a regular diet of whole prey; a low-calcium diet with boneless prey; and a diet with boneless prey and a calcium supplement. After several meals, the team studied the effects of each regimen on the snakes' intestines.

The team found that narrow, specialized cells in the pythons' intestinal lining played a role in digesting bones. In the snakes that ate whole prey or boneless prey with a calcium supplement, these cells held particles made up of calcium, iron and phosphorus. But these particles weren't present in snakes that only ate boneless prey.

Related: 'An up-tempo version of Darwinian evolution': How a mega freeze in Florida may have caused Burmese pythons to evolve at a blindingly fast speed

The cells may be involved in dispelling calcium that the snakes couldn't absorb. It's possible that the cells could concentrate the extra calcium into the particles, then release the particles alongside other undigested components into the snakes' feces, the researchers wrote in the study.

Since discovering the narrow intestinal cells in Burmese pythons, the scientists have also found them in the intestines of other pythons and boas, as well as in Gila monsters (Heloderma suspectum) — all of which eat their prey whole. But there's no evidence yet that other animals that swallow their entire prey, such as dolphins or fish-eating birds, produce these calcium particles.

Further studies could reveal just how widespread these bone-digesting cells are in the animal kingdom, the researchers wrote.

"Marine predators that eat bony fish or aquatic mammals must face the same problem" of digesting bones and ridding themselves of excess calcium, Lignot said in the statement. "Birds that eat mostly bones, such as the bearded vulture [Gypaetus barbatus], would be fascinating candidates too."

A Florida bobcat has managed to take down a Burmese python in what wildlife biologists are calling a win for native Everglades predators.

Scientists are still investigating how and when local predators face off against the invasive snakes, but the finding hints that native species are learning to take advantage of the competition as a potential food source.

The snake's remains were found near the city of Naples in December 2022 by wildlife biologist Ian Bartoszek of the Conservancy of Southwest Florida.

Since 2013, he and his colleagues have used radio trackers to keep tabs on male Burmese pythons, and during breeding season, these male "scout" snakes lead researchers to fertile female snakes and their eggs. From there, researchers remove and euthanize the reptiles in an attempt to cull the invasive population.

On that chilly December day, Bartoszek's team was tracking Loki, a 13 foot (4 meters) long, 52 pound (23.5 kilogram) scout snake. They expected to find Loki holed up with a female python. Instead, they found his freshly slain body, with the head and neck gnawed off and buried beneath pine needles nearby.

"It was a bit sad and a bit exciting at the same time," said Bartoszek, who had tracked Loki through six breeding seasons. "We sort of treated it as a bit of a CSI crime scene."

The team immediately started to look for clues as to what had killed the massive snake. The way Loki's neck had been chewed and his head buried suggested a large cat — either a bobcat or a Florida panther — as the culprit.

Bartoszek contacted wild cat expert David Shindle, of the US Fish and Wildlife Service, who set up a trail cam near the kill site in case the cat came back for its buried meal. The next morning, it did — and its behavior was caught on video.

"All of a sudden, out of the background, an adult bobcat comes walking in across a log," Bartoszek described. "You could see it sort of sniffing the air, probably picking up on our scent, seeing what information it was clueing-in to, and basically returning to the kill site."

Burmese pythons have been known to eat bobcats, but Bartoszek suspects this particular bobcat seized an opportunity to pick off Loki while he was incapacitated. A cold snap had hit southern Florida a few days before the scientists found the snake's remains. And since male snakes are usually out and about looking for females during breeding season, the chilly weather may have left the cold-blooded Loki stunned and sluggish, far from his usual warm burrow and unable to fight off the predator.

Working on the front lines of these wildlife studies offers the chance to observe new and interesting predator-prey interactions, Bartoszek told Live Science. "It felt like 'score one for the home team,' where our native animals are fighting back," he said. "That's a good sign."

These kinds of predation events are likely becoming more common in the Everglades, Bartoszek said. His team found the remains of a different scout snake after another cold snap earlier this season, this one likely killed by a black bear.

Researchers are still collecting evidence and looking for trends in how predators like bobcats and bears might be turning the tables on pythons.

"There's a bit of a pattern emerging that — and you'd expect as much — over time, the ecosystem is rebalancing itself. It's fighting back," Bartoszek said. "These native predators are recognizing Burmese pythons as a new food source and are able to take advantage of some of their vulnerabilities."

Snake quiz: How much do you know about the slithering reptiles?

Fifteen years ago, a cold snap froze much of Florida's wildlife to death — including many of the state's invasive Burmese pythons (Python bivittatus). But in this excerpt from "Slither: How Nature's Most Maligned Creatures Illuminate Our World" (Gand Central Publishing, 2025), science writer Stephen Hall reveals that a subset of these pythons were genetically predisposed to survive the cold, setting the stage for rapid evolution that could help the invasive snakes spread further into North America.

In early January 2010, a historic and prolonged deep freeze swept across the southeast United States, reaching all the way into the subtropical Everglades. Temperatures hovered around 50 degrees Fahrenheit (10 degrees Celsius) for 48 hours; on Jan. 11, thermometers in South Florida dipped as low as 24.8 F (minus 4 C). Most people remember it, if at all, for the frozen iguanas that dropped out of trees and photos of citrus trees encased in icicles, like some fugitive Minnesota winter carnival smuggled into the Deep South.

But to wildlife and invasive species experts, the Big Freeze marked the start of the Big Unplanned Experiment.

The immediate impact on the Burmese python population was clear. Carcasses of dead snakes littered roads; frozen specimens turned up in underground burrows; farther north in South Carolina, in the infamous "Where's Waldo" python enclosure, all 10 snakes perished during the regional cold snap.

Researchers attributed the mass die-off to "maladaptive behavior," meaning many snakes tried to bask above ground in the sun despite the frigid temperatures, rather than seeking thermal shelter in underground or aquatic burrows. Python "removals" — captures by hunters, which served as a rough indication of the general population — had peaked in 2009 in the national park but plummeted almost five-fold in the following two or three years. It all looked like good news, at first.

But population numbers were still lacking, and "models" are still just models. Genes are where the rubber of biology meets the road of environmental challenge, and this is when the geneticists entered the story. They were less interested in the many snakes that had died, and more interested in the few that had survived.

Like all snakes, Burmese pythons are ectotherms — they rely on warmth from the environment because they do not generate their own metabolic heat — so they have to develop biological tricks in their behavior or in their physiological resilience in the face of life-threatening cold to survive freeze events that do not occur in their native range. As the United States Geological Survey (USGS) overview put it, "some portion of the southern Florida population survived" the 2010 event, "and these snakes and their offspring make up the current population."

By 2014, the number of python removals in Everglades National Park had returned to pre-freeze levels. In genetic parlance, the 2010 freeze was a "bottleneck event" — only a few squeezed through and survived. But the ones that did, in the biblical sense, went forth and multiplied.

Beginning around the year 2015, several researchers studying python genomes to understand their metabolism became curious about the after effects of the big freeze. Daren Card and Todd Castoe of the University of Texas at Arlington teamed up with Maggie Hunter of the USGS office in Fort Lauderdale to look for evidence of what is called rapid adaptation, which might be thought of as an up-tempo version of Darwinian evolution.

They examined the DNA of these survivor snakes to see if there were any genetic clues as to why certain pythons were able to withstand an extended freeze; more precisely, they compared the DNA of pythons that lived before the freeze event with the DNA of pythons that had survived to see if they could identify any differences that might explain the resilience of the survivors at the molecular level.

The short and disturbing (although not definitive) answer was: yes.

It turns out that the survivors seemed to share genetic changes in areas of their genomes known to control thermoregulatory behavior and metabolism. "We saw a lot of things that just fortuitously overlapped with a lot of the same sorts of pathways and genes that we were studying in parallel, in a much more controlled fashion, using more lab experiments in Todd's work on Burmese pythons," Card told me. "As we delved into them, we started to see a lot of genes that are involved in things like thermal tolerance."

The findings, published in 2018, suggested that the survivors shared variations in their genetic makeup that seemed to confer greater cold tolerance and greater metabolic flexibility — two traits that Castoe's lab had been investigating since 2011. These snakes were more inclined behaviorally to seek shelter in underground refugia to outlast the cold — a good adaptation to the environmental reality of occasional freezes. And the metabolic changes seemed to favor a behavior that encouraged smaller and more frequent meals — a good adaptation to the ecological reality that, having already decimated populations of large mammals in the Everglades, the pythons might need to modify their diet.

This is not definitive news — the study was small, no one (surprisingly) has followed up on it, and, as Card put it, researchers still only have a view from 30,000 feet of what happened on the genetic level in the pythons that survived the Big Freeze. Whatever it is, the genetic changes — or, more accurately, the selection for genes that enhanced survival — appears to have happened very quickly. And that is, possibly, very bad news. It suggests that the pythons are on the move, genetically as well as geographically.

The implication is that the 2010 freeze acted as a huge selection event, as evolutionary biologists put it — an environmental stress so dire, so extreme, that it has the effect of rapidly winnowing out individuals holding a bad genetic hand and "selecting" the lucky ones that hold winning genetic hands.

The freeze culled out individuals that were susceptible to cold temperatures and selected individuals that possessed, at the genetic level, some form of cold-hardiness. Those genes were presumably passed down — immediately, profligately and of course, cryptically — to their hundreds of offspring.

The suggestion of rapid adaptation in the Burmese python population in Florida again contradicts our traditional notions of evolution as a glacial process of genetic selection and refinement that requires millennia, eons and geological epochs. "We typically think of evolution as occurring over generally quite long time scales, on the order of several generations at the low end up to potentially thousands to millions of years," Card said. "I think with a lot of the tools that we've developed more recently, especially in things like genomics, people have taken a harder look at how quickly evolution can occur… And generally, when you see such an extreme thing occurring, it really suggests that there's very strong selection. Something's happening."

In fact, Castoe believes the importation of so many pythons from so many different regions of Asia — all packing in their biological luggage a wide variety of genetic variants, known as alleles, for their trip to North America — set the table for a rapid genetic adaptation. As Castoe put it: "If you've got a good amount of genetic variation, given strong selection, this can happen in a heartbeat. 'If I've got the allele, what the hell am I waiting for? I ain't waiting for nothing!'"

At a time when roughly 40% of Americans do not accept the notion of evolution, the pythons that survived the Big Freeze in Florida appear to believe in it 100%. The take-home genomics message from the snakes is that evolution is real, it's apparently happening at blindingly fast speed, and it argues that the 2010 cold snap may have created a subset of pythons better able to survive cold temperatures — and thus better adapted to spread beyond the northern boundaries of its current range.

Excerpted from SLITHER: How Nature’s Most Maligned Creatures Illuminate Our World ©2025 Stephen S. Hall and reprinted by permission from Grand Central Publishing/Hachette Book Group.

Do you ever wish you could just crawl out of your own skin? Snakes are some of the few creatures on Earth that actually can. Dozens of times throughout its life, a snake slithers out of its old skin in a process called "ecdysis," leaving behind papery sheds delicately imprinted with the unique pattern of its scales.

It's not unusual to shed skin; humans do it, too. "But unlike us, whose skin sheds off in little flakes, snakes produce a whole new layer of skin, and the old layer of skin falls off in one big slough," said Jason Dallas, a postdoctoral researcher who studies bacterial-fungal interactions in snakes and amphibians at Middle Tennessee State University.

But why do snakes shed their skin, and why does it happen in one go?

Snake skin is composed of two main layers. The inner, softer layer — called the dermis — contains the pigments that give snakes their intricate colors and patterns. The dermis is covered in the epidermis, a tougher layer of semitransparent keratin scales.

The outer layer of human skin also contains keratin, but the structure of our skin allows it to flake off in individual scales, which are almost invisible to the naked eye. In snakes, the exterior keratinous layer forms a unit, which creates a sheath-like covering that's bound to the snake's more delicate dermis below.

Related: What are the world's deadliest snakes?

The trade-off of this hardy external layer is that it doesn't expand; it remains relatively inflexible and constricts the snake as it grows. This is one of the primary reasons snakes shed their skin: to create more room. Snakes grow more quickly when they are younger, so they also shed more in youth.

In fact, snakes' first shed happens "within a few days of hatching or being born," Daniel Kane, senior reptile keeper at the London Zoo, told Live Science in an email. By adulthood, snakes typically shed around three or four times a year, Kane said.

When a snake is almost ready to shed, it starts to develop a second fresh keratin layer atop the dermis and below the original keratin sheath. It also secretes a fluid to help loosen the old layer from the new one. As this process unfolds, the snake typically finds a rough spot to rub its head against. This creates a slit in the old skin, through which the snake can then start to slither out.

With the help of continued rubbing and muscle spasms, the snake eventually loosens its entire skin and escapes the wrinkled relic with a set of glossy new scales. A fresh shed may be up to 20% longer than the original snake, as this recently lubricated skin is "quite stretchy before it dries out and becomes brittle," Kane explained.

Once the skin is shed, the snake discards it and slithers away. Although snakes don't typically eat their skins, some other reptiles do, such as lizards and geckos, to regain lost nutrients.

Shedding is associated with big life events, such as a snake's emergence from a long hibernation, or reproduction. "They typically will shed right before they either lay their eggs or give live birth, and then they may shed again after that period," Dallas told Live Science. "So it typically is synced up with life history events in adults."

Interestingly, snakes also use shedding to deal with unwanted parasites, infections and disease, Dallas said. One common example is snake fungal disease, which poses a significant threat to snakes worldwide.

"The pathogen is able to colonize deeper tissues as well as internal organs," Donald Walker, an assistant professor of biology at Middle Tennessee State University and principal investigator of the lab where Dallas works, told Live Science. "It's thought to be able to get the eyes, and maybe even the brain, of the animal. … But it starts by colonizing the skin and feeding on keratin and lipids in snake scales." Shedding could be lifesaving in cases like this. Yet the ability to shed skin also incurs a cost. Not only is it an energy-intensive process, but the trailing skin may hinder the snake's hunting prowess by disturbing its vision. Snake eyes appear clear, but they're covered by a single, bubble-like, keratin scale.

"The transparent scale, known as the 'spectacle,' protects the snake's eyes from day-to-day scratches and abrasions as it moves headfirst through the world," Kane said. "When the snake is in the process of sloughing off its skin, vision is impaired by the cloudiness caused by the secretions used to separate the old from the new layers."

A less-mobile, sight-impaired shedding snake is typically more vulnerable to predators, too. So ideally, a snake should not be shedding too frequently.

Disease might complicate snakes' natural shedding schedules and turn this survival tactic against them — particularly in species such as the eastern massasauga rattlesnake (Sistrurus catenatus) in the United States, Dallas said.

"These snakes are very susceptible to the fungus that can obscure their eyes and their mouth, but also increased shedding rates can increase their risk of predation," Dallas said. "And this has caused relatively large population declines in some populations of the species."

Overwhelmingly, however, a snake's shedding ability is vital to its survival. In the wild, discarded skins can also help scientists and conservationists protect these reptiles, by offering telltale genetic fingerprints and other clues that enable them to detect threats to snake health, study population numbers and species biodiversity.

"Snake skin often contains a faint version of the pattern of the snake and the specific number and arrangement of scales, meaning it's often possible to identify a species based on a shed skin," Kane said.

Of all animals, snakes produce the most instantly recognizable shed specimens in the wild. But they share their shedding ability with all other reptiles, which, unlike their serpentine cousins, mostly release their skins in fragments. There are some exceptions, however. For example, lizards from the Abronia genus are small, dragon-like creatures that wriggle out of their skins and leave behind a perfectly intact replica, legs and all.

Snake quiz: How much do you know about the slithering reptiles?

Snakes are limbless reptiles that are found on every continent except Antarctica, having adapted to a wide range of environments. They are amazing creatures with some jaw-dropping abilities, and they play a critical role in many food webs.

While most snakes are completely harmless, some inspire dread for good reason. Globally, 5.4 million people are bitten by snakes every year, resulting in between 80,000 and 140,000 annual deaths, according to the World Health Organization.

Of the 4,000 snake species in the world, only about 600 are venomous, though not all of those pose a threat to humans. That doesn't stop some people from developing ophidiophobia, or an intense fear of snakes, which is one of the most common phobias.

Without further ado, how much do you know about snakes?

Remember to log in to put your name on the leaderboard; hints are available if you click the yellow button, and let us know your score in the comments. Good luck!

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In a first-of-its-kind discovery, a death adder has been found with three super-sharp, venomous fangs, instead of the usual two.

"This is something we've never seen before," Billy Collett, park manager at the Australian Reptile Park, where the snake lives, said in a statement emailed to Live Science. "We've had this death adder in the venom program for about seven years, but only recently did we notice the third fang. I thought it would just shed off over time, but one year later, and it's still there!"

This third fang, located right next to one of the other fangs at the left side of the snake's mouth, also produces venom. This means it has a much larger venom output per bite than is usual for a death adder, making it even more deadly.

This ultra-rare snake "might actually be the most dangerous death adder in the world," Collett said in a video interview. According to the statement, the extra fang is the result of a never-before-seen mutation.

Related: 'Truly primal': Watch Burmese python swallow deer whole in Florida Everglades by stretching its mouth to the absolute limit

Death adders (Acanthophis) are a group of venomous snakes native to Australia and New Guinea. They have one of the fastest strikes of any snake, with some species being capable of biting and injecting venom from their fangs in under 0.15 seconds. Their venom contains neurotoxins that can cause paralysis and even death if left untreated. Before the development of antivenom, around 50% of death adder bites were fatal.

This snake is part of Australian Reptile Park's antivenom production program, and its extremely rare extra fang was discovered when it was being milked for its venom. This involves gently squeezing a snake's venom glands while it bites onto a collection container, causing the venom to pour into the vial.

This three-fanged death adder was found to produce far more venom than usual, with "massive yields" coming out of all three fangs. It produces roughly double that of a two-fanged death adder — although it's unclear whether the higher yield is the result of the extra fang, or that this individual just produces high quantities of venom.

This is the first three-fanged snake ever discovered at the Australian Reptile Park, which has been operating for 20 years and has milked hundreds of thousands of snakes, a spokesperson for the park told Live Science in an email.

"There have been other 3 fanged snakes found in Australia, but from what we can find, there have been no 3 fanged death adders recorded," they said.

Exactly why this snake has three fangs instead of two is unclear, but may be related to the process of fang replacement. Similar to human adult teeth, death adders have replacement fangs growing behind the active ones, so when a fang is lost, a new one moves forward to take its place. This ensures that their fangs remain sharp and functional for injecting venom.

"It's normal for death adders to shed fangs over time and replace them with new ones every few months or so," the spokesperson said. "Unfortunately, we don't actually know what has caused the 3rd fang to develop and don't currently have the facilities to run any tests."

There are about 4,000 different snake species in the world today. They occupy a wide range of habitats — some dwell underground while others live high in the canopies of trees, and many spend their entire lives on the ground. Some even spend a significant portion of their lives underwater. They have adapted to climates ranging from tropical rainforests and deserts to marine environments and the freezing Arctic.

These legless reptiles evolved from four-legged lizards during the Jurassic period (201 million to 145 million years ago). Like nearly all living reptiles, snakes are cold-blooded, meaning they rely on the environment to regulate the temperature of their bodies. As a result, snakes are frequently seen warming themselves in the sun.

Though snakes are often thought to be dangerous, only around 600 species are venomous, about a third of which possess venom that is fatal to humans, according to National Geographic. Even these species are inclined to avoid humans and only strike when threatened. Most snakes are entirely harmless, and they are all crucial predators that help maintain food webs.

4 fast facts about snakes

• Snakes smell by flicking their forked tongues and picking up odors that are transported to special organs on the roofs of their mouths.
• Snakes do not have eyelids. Each eye is covered by a clear membrane that is periodically shed along with the skin.
• Some species of snake have the remnants of legs in the region where their lizard ancestors would have had legs.
• All snakes shed their skin. They do this to grow and remove parasites.

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We don't know exactly when the first animals on Earth appeared, but it's thought to be around 700 million years ago. Around 541 million years ago, at the start of the Cambrian period, hundreds of thousands of new species appeared within a span of about 20 million years — an event known as the Cambrian explosion. Since then, millions — or possibly billions — of species have come and gone. Scientists estimate that 99.9% of all creatures that ever lived have gone extinct.

Researchers think there are now around 7.7 million animal species living on Earth, with thousands more discovered every year. But species are also going extinct at an alarming rate, with many likely vanishing before they've even been formally recognized. Many scientists even say we're entering a sixth mass extinction.

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The mighty king cobra — the world's longest venomous snake — is actually four distinct species, scientists have confirmed in a new study.

For 188 years, the king cobra has been represented by a single species, Ophiophagus hannah. But this widely distributed species shows huge differences in body coloration and other physical characteristics across different regions, leading scientists to question whether it is a single species.

In a study published in 2021, scientists confirmed genetic differences among king cobra populations. Building on this research, scientists have now compared physical differences in museum specimens and identified four separate species: the Northern king cobra (O. hannah), the Sunda king cobra (Ophiophagus bungarus), the Western Ghats king cobra (Ophiophagus kaalinga) and the Luzon king cobra (Ophiophagus salvatana). The findings were published Oct. 16 in the European Journal of Taxonomy.

"I feel like we created history," study author Gowri Shankar Pogiri, founder of the Kalinga Foundation and director of the Kalinga Centre for Rainforest Ecology, told Mongabay.

Related: Evolution of snakes takes surprise twist — cobras didn't come from where we thought they did

King cobras live in humid environments, including open forests and dense mangrove swamps, from northern India to southern China and throughout Southeast Asia. Across these regions, their appearance varies in body color, pattern and size.

In the 2021 study, a DNA analysis that accounted for almost the entire distribution range of king cobras identified four distinct genetic lineages. These lineages were classified as confirmed candidate species — species yet to be formally described and named.

Building on this research, the new study looked at the physical differences among 153 museum specimens. An analysis of the specimens' body morphology — including their color patterns, body widths and dental characteristics led the researchers to identify four species corresponding to the genetic lineages found in the 2021 study.

The Northern king cobra (O. hannah) is widespread across the sub-Himalayas, eastern India, Myanmar and Indochina, and extends southward to the narrowest part of peninsular Thailand, in Kra Isthmus. Adults have dark-edged yellow bands and between 18 and 21 teeth.

The Sunda king cobra (O. bungarus) lives in the Malay Peninsula and the islands of the Greater Sundas — including Sumatra, Borneo and Java — as well as in Mindoro in the Philippines. Large individuals of this species are usually unbanded or have narrow, pale bands with dark edges along the body.

The Western Ghats king cobra (O. kaalinga) is restricted to the Western Ghats of the Indian Peninsula. This species differs from O. bungarus in that it does not have dark edges around the pale bands along its body.

Like O. kaalinga, the Luzon king cobra (O. salvatana) inhabits Luzon, an island in the northern Philippines. It has extremely angular pale body bands compared with the bands of the three other species.

All of these species are venomous. King cobras are amongst the most venomous snakes in the world and release a large dose of venom in a single bite that can kill a human in as little as 15 minutes. The new study shares that this could be the first step in developing improved antivenom from Ophiophagus bites in their respective regions.

Pogiri believes there may be more unknown king cobra species yet to be discovered on small islands that were not part of this research. "Studying them is already underway," he said.

A huge Burmese python has been found swallowing a deer whole in Florida's Everglades. The impressive feat challenges what gape models suggest the invasive snakes are physically capable of.

"It felt like we were literally catching the serial killer in the act and it was intense to observe [in] real time," Ian Bartoszek, a wildlife biologist and science coordinator at the conservation organization Conservancy of Southwest Florida, told Live Science in an email.

The female Burmese python (Python bivittatus) measured 14.8 feet (4.5 meters) long and weighed 115 pounds (52 kilograms). It was discovered feasting on a white-tailed deer (Odocoileus virginianus) that weighed 76.9 pounds (35 kg) — almost 67% of the snake's mass. To devour the deer, the snake's mouth stretched so wide it reached 93% of its maximum gape, according to a study published Aug. 22 in the journal Reptiles & Amphibians.

"This was the most intense and impressive sight we have observed in 12 years of tracking pythons in southwestern Florida," Bartoszek, one of the study authors, said. "It was truly primal and felt like a scene that had been playing out for millions of years wherever you have large snakes. Unfortunately our native wildlife in Florida have not evolved with this apex predator and you are seeing that result with these images."

Related: The biggest snake in the world (and 10 other giant serpents)

Burmese pythons are an invasive species in the Everglades and were introduced at some point in the mid to late 20th century. The first sighting was in 1979, and by the 1990s they had gained a stronghold, feasting on native species while having no natural predators to control their population. While the current population size is unknown, experts estimate there could be hundreds of thousands in Florida. Over the last few decades, Burmese pythons have decimated local ecosystems, wiping out several mammal species.

Burmese pythons are known to eat deer and even alligators, but finding the predators in the act is challenging, limiting how much scientists know about what these apex predators are capable of eating, and therefore how much of an impact they're having on the ecosystem.

Related: Which animal has the stretchiest mouth?

According to the study, the previously assumed maximum gape for a Burmese python (the width it can open its jaws) was around 8.6 inches (22 centimeters). However, the researchers examined three of these snakes — including the 14.8 foot python — and found they had a maximum gape of 10.2 inches (26 cm). The discovery has "significantly affected" models showing what Burmese pythons are physically capable of swallowing, the researchers wrote.

"These observations and this study serves as another warning sign to the threat imposed on the Everglades ecosystem by the Burmese python," Bartoszek said.

Burmese pythons can swallow huge prey because their jaws aren't fused at the front, which enables them to stretch far wider than similar-sized snake species. "Our anatomical measurements indicate this deer was very near the size limit on the prey that could be consumed by this snake," study author Bruce Jayne, professor of biological sciences at the University of Cincinnati, said in a statement emailed to Live Science. "Hence, these snakes resemble overachievers by sometimes testing the limits of what their anatomy allows rather than being slackers that eat only 'snack size' prey."

The deer-eating snake was located with the help of a male python called Ronin. Ronin is fitted with a tracking device that leads researchers to females — part of a program that releases males as "scout snakes" during the breeding season. Burmese pythons are prolific breeders, with each female able to produce dozens of eggs each season. Removing females is a way of controlling the population.

"Each breeding season [Ronin] leads us to multiple females that we humanely remove before they have a chance to lay eggs," Bartoszek said. "All of the pythons we remove are humanely euthanized. We have a lot of respect for the Burmese python and they are here through no fault of their own. However we understand the impact they are having on native wildlife and are not sitting on the sidelines."

When wildlife officials in Georgia stumbled upon a pair of seemingly lifeless snakes that had been vomited up by another, larger snake, they were already surprised by what they had found. But things took an even weirder twist when one of the regurgitated serpents suddenly woke up and slithered off.

Wildlife technicians from Georgia's Department of Natural Resources (DNR) came across the unusual scene in November 2023 while surveying federally protected eastern indigo snakes (Drymarchon couperi) in southern Georgia, according to a DNR Facebook post written on Aug. 29.

The team found a live 4-foot-long (1.2 meters) indigo snake alongside two other snakes — a "young rat snake" and a juvenile eastern diamondback rattlesnake (Crotalus adamanteus) — that had both "clearly [been] swallowed and then expelled" by the larger snake, DNR representatives wrote.

Related: The biggest snake in the world (and 10 other giant serpents)

While the rat snake did not survive being eaten, the regurgitated rattlesnake eventually showed signs of life around an hour after it was found, and it didn't seem to be particularly bothered by the ordeal. "It was later seen basking in the sun instead of taking shelter in a burrow," DNR representatives wrote.

If that wasn't odd enough, the wildlife experts soon realized that the rattlesnake also had a large bulge in its midsection, suggesting it had recently swallowed a mouse whole.

"This unusual episode not only reveals the indigo's impressive hunting abilities but also the rattlesnake's unexpected resilience," DNR representatives wrote.

Snakes eating one another whole is nothing new, and the size of the meal is rarely an obstacle.

For example, in June 2022, a Georgia resident filmed an eastern kingsnake (Lampropeltis getula) slowly eating a much larger timber rattlesnake (Crotalus horridus). A study released in August this year also documented an incident where a Burmese python (Python bivittatus) swallowed a larger reticulated python (Malayopython reticulatus) from the tail up.

However, eating such massive prey also comes with risks, such as choking.

In February 2022, a rim rock crowned snake (Tantilla oolitica) was found dead in Florida after choking on a centipede, which was still lodged in its mouth when it was discovered. And in September last year, a herpetologist in France stepped in to save a viperine snake (Natrix maura) that was choking on an invasive fish.

In the recent case, the indigo snake may have been trying to avoid a similar fate when it expelled its two victims. However, it is also possible that it voluntarily surrendered its meal to escape a predator or because it was stressed out by the nearby wildlife experts looking for it.

Tarantulas are hairy so that the army ants cleaning their homes don't eat them alive, a new study suggests.

The study, published Aug. 6 in the Journal of Natural History, proposes several new ideas about tarantula relationships with other species, including their surprisingly passive but still occasionally violent interactions with predatory ants.

Predatory ants, or army ants, are known to hunt spiders alive, but when these ants were observed scavenging for food in South American tarantula burrows, the ants tended to ignore adult tarantulas as well as tarantula offspring. In the rare instances when the ants did attack, the tarantulas' stiff hairs offered adequate protection.

"The dense hair covering the tarantula's body makes it difficult for the ants to bite or sting the spider," study lead author Alireza Zamani, an arachnologist at the University of Turku in Finland, said in a statement. "Therefore, we believe that the hairiness may have evolved as a defence mechanism."

Related: Deadly male funnel-web spider 'Hercules' breaks record as biggest ever discovered

Zamani and his colleagues explored the complex relationships between tarantulas and other animals by reviewing previous scientific studies and gathering new observations from the field and social media.

The researchers found that army ants help fossorial tarantulas — those that live in burrows — by removing old food from their burrows. However, the spiders still needed protection in case the ants got bitey. This hair-defense hypothesis is supported by previous studies that suggested burrowing tarantulas cover their egg sacs in hairs to help stop ants from getting at them.

Furthermore, the team discovered that less hairy — and therefore potentially more vulnerable — arboreal tarantulas, including Avicularia hirschii in Peru, have developed different defense strategies against ants. For example, in one observation, the researchers watched A. hirschii hang from the tip of a leaf to escape ants on the hunt for prey, according to the statement.

While tarantula-ant relationships can get strained, the researchers found that tarantulas enjoy friendlier interactions with amphibians, which sometimes live in their burrows. The study described more than 60 partnerships between tarantulas and amphibians across 10 different countries, as well as relationships with snakes and other spiders.

"Apparently, the frogs and toads that live within the retreats of tarantulas benefit from the shelter and protection against their predators," Zamani said. "In turn, they feed on insects that could be harmful to the spider, its eggs, and its juveniles. It seems that tarantulas might not be as scary and threatening as their reputation suggests."

A Burmese python has been spotted attacking and swallowing a reticulated python. The unusual encounter could be the first known case of these species — two of the world's biggest snakes — preying on one another, scientists say.

Researchers in India observed the rare event in 2020, and images captured the moment the Burmese python (Python bivittatus) began feasting on the reticulated python (Malayopython reticulatus) from the tail up, while it was still alive. It took about two hours for the snake to be completely consumed, scientists reported in a research note published Aug. 20 in the journal Reptiles and Amphibians.

"It was a really unusual situation to find two pythons in the same area," study co-author Ashikur Rahman Shome, a wildlife ecologist at Dhaka University in Bangladesh, told Live Science.

When the scientists arrived, the 10-foot-long (3 meters) Burmese python was coiled around the slightly larger reticulated python's tail. The latter tried to fight back by constricting the Burmese python, but it eventually loosened its grip and was swallowed from the tail end up.

Related: The biggest snake in the world (and 10 other giant serpents)

Burmese pythons can grow to 19 feet (5.8 m), while reticulated pythons can reach up to 25 feet (7.6 m). In thi case, the reticulated python was larger than the Burmese, but the exact length was not taken, Shome said.

The event took place on the Akiz Wildlife Farm in Bangladesh's Chittagong Division. This area is one of the few places where the ranges of Burmese and reticulated pythons overlap. The two snake species prey on similar animals, such as mammals, birds and lizards.

It's not completely clear why the reticulated python was eaten, but given the better food options at the site, it might just have been a territorial dispute that ended up with one eating the other as an easy way to end the fight: "There are a number of chickens at the site. They make a better meal," Shome said.

"To the best of our knowledge, this observation represents the first documented predation of M. reticulatus by P. bivittatus," the team wrote in the paper.

"When the cobra runs for her life, she goes like a whiplash flicked across a horse's neck," Rudyard Kipling wrote of the villainous cobra Nagaina in his story of the heroic mongoose Rikki-Tiki-Tavi. And this whiplash motion may have helped real-life cobras and their relatives spread from Asia, where they originated, to the rest of the world.

Scientists once believed that Elapoidea, the superfamily containing cobras, coral snakes and mambas, originated in Africa. A fossil of a file snake found in Tanzania and dated to the Oligocene Epoch (33.9 million to 23 million years ago) supported this hypothesis — it is the oldest relative of this group discovered in the fossil record.

But in new research, published Aug. 7 in the journal Royal Society Open Science, researchers used genetic analysis and fossils from other regions to conclude that these snakes, as well as snakes in the related superfamily Colubroidea, actually originated in Asia.

"The reason for the uncertainty was mostly because of the lack of understanding of how these different species are related to one another," lead author Jeffrey Weinell, an evolutionary biologist and postdoctoral fellow at the American Museum of Natural History, who conducted the research while at the University of Kansas, told Live Science.

Related: 50-foot 'king of the serpents' may have been the biggest snake to ever live

Scientists had never compiled comprehensive genetic data on the group before, he explained. "I was interested in inferring the tree of life for this group, which predicts the evolutionary relationships, and then using that tree of life estimate plus information about modern species to estimate where the ancestor of this group lived," he added.

In the new study, Weinell and colleagues analyzed 3,128 locations on the genomes of 65 species of Elapoidea to decipher how all the snakes were related. They also included additional data from 434 other species, some of which had already been compiled in genetic databases and some of which they sampled themselves. These species were then mapped to depict their historical geographic distribution.

They found that the earliest ancestors of Elapoidea evolved in Asia between 28.94 and 45.92 million years ago and that Colubroidea emerged some 31.13 to 48.81 million years ago.

These early Asian ancestors may not exist in the fossil record due to the conditions where they evolved. "Tropical Asia is not the best for preserving fossils because of the climate," Weinell said.

These snakes left Asia for Africa, between 37.5 million, at the earliest, and 24.4 years ago and their descendants then dispersed into Europe, Australasia and the Americas in multiple waves. There are now 700 species, on every continent except Antarctica and many islands as well. Even the seas have been colonized by these early snakes' descendants.

The study found these snakes had a convoluted evolutionary history. Elapoids and colubroids likely moved into Africa from Asia on at least 15 different occasions, for example. And they recolonized Asia from Africa at least seven times, indicating the complexity of their movement between landmasses and underscoring the difficulty of tracing their origins.

As to how they got from one continent to the other, Weinell suspects that these snakes may have taken a variety of paths — using land bridges and even crossing narrow marine passages, to achieve their global distribution today.

A captive snake in Australia has broken the world record for the most venom produced in one go, according to the creature's keepers.

With a single bite, the snake — a coastal taipan (Oxyuranus scutellatus) named Cyclone — ejected more than 0.18 ounces (5.2 grams) of venom. That's three times the average amount produced by a coastal taipan and enough to kill 400 humans, according to the Australian Reptile Park, a zoo located 30 miles (50 kilometers) north of Sydney in New South Wales.

"Cyclone is one of our most dangerous snakes here at the park and is known for being quite unpredictable and keeping us all on our toes," Billy Collett, the operations manager at the Australian Reptile Park, said in a statement shared with Live Science.

Coastal taipans are one of the most venomous snake species on Earth. They are native to coastal regions in northern and eastern Australia and typically grow to 6.6 feet (2 meters) long, according to the Australian Museum. Coastal taipans have a rectangular head with a pale snout and large, orange-brown eyes. Their bodies vary in color from yellow to reddish-brown, dark brown and almost black.

Related: Why does Australia have so many venomous animals?

"Coastal taipans are not the most venomous snake in the world, but they are known worldwide for their aggression and bites have caused fatalities every year," Collett said.

The previous venom yield record belonged to another coastal taipan at the park called Whiplash, which produced 0.17 ounces (4.9 g) of venom from a single delivery in 2022.

The park is the only facility in Australia that "milks" taipans to produce antivenom, Collett said. Keepers also extract venom from other deadly snakes, including eastern brown snakes (Pseudonaja textilis), tiger snakes (Notechis scutatus), death adders (Acanthophis) and black snakes (Pseudechis).

Milking snakes can be dangerous, according to the statement. "The process of milking a venomous snake requires keepers to secure the … snake, sink its fangs into a large shot glass covered with plastic and get it to deliver its lethal bite," Collett said. The venom is then freeze-dried, meaning it is dehydrated at low temperature, and sent to a vaccine manufacturer, Collett said.

Cyclone's record-breaking venom contribution will go toward saving someone's life, according to the statement. Around 3,000 snake bites are reported every year in Australia, resulting in approximately 500 hospital admissions and an average of 2 deaths. According to the Australian Snakebite Project, coastal taipans bit 31 people between 2005 and 2015, and although no deaths were found in that project, another study recorded at least one death between 2000 and 2016.

A captive snake thought to be male recently gave birth to 14 babies after almost a decade in isolation, its keepers say. 

The 13-year-old Brazilian rainbow boa (Epicrates cenchria), named Ronaldo, has not been in contact with any other snake for at least nine years. Ronaldo was a rescue snake that a vet had previously identified as a male. 

"One of the students discovered them during a routine vivarium check," Amanda McLeod, an animal care technician at the City of Portsmouth College in the U.K., where the snake is kept, said in a statement Monday (June 24). "At first we thought she must have been mistaken. We couldn't believe our eyes!"

This is the third  "virgin birth" recorded in a Brazilian rainbow boa. 

"Ronaldo had been looking slightly fatter than usual, like he'd eaten a big meal, but we never thought for a moment that he, or should we say she, was pregnant," Pete Quinlan, a reptile specialist at the college, said in the statement. 

Related: 8 animals that have virgin births

Virgin birth, known as parthenogenesis, is a type of asexual reproduction that takes place in a species that normally reproduces sexually. While rare, it's been recorded in several species in captivity, including birds, sharks, lizards, other snake species and a crocodile. 

In parthenogenesis, eggs mature without fertilization by sperm. In some cases, eggs can be fertilized by a "polar body," which is a small cell that forms in the reproductive tract at the same time as an egg cell. 

There are several different ways parthenogenesis can occur, and it is unclear what mechanism triggered Ronaldo to produce offspring. 

"Effectively the babies are clones of their mother although their markings are all slightly different," Quinlan said. 

Ronaldo was brought to City of Portsmouth College after being rehomed there by an animal welfare charity. The snakelets are now being assessed to determine their sex and placed in new enclosures. Once large enough, they will be rehomed, according to the statement. 

Snake Island is a small, forested island off the coast of Brazil that writhes with thousands of venomous vipers. The snakes, which grow up to 3.9 feet (1.2 meters) long, are golden lancehead pit vipers (Bothrops insularis). They are so venomous, the Brazilian navy has closed the island to the public since the 1920s. 

The island sits about 21 miles (34 kilometers) off the coast of southeastern Brazil and covers an area of 106 acres (43 hectares), which is equivalent to about 80 American football fields. Rainforest blankets more than half of the island, while the rest is barren rock and grassland.

Snake Island was once connected to the mainland, but rising sea levels submerged the land bridge around 10,000 years ago, at the end of the last ice age. This separation trapped a population of golden lanceheads on the island, where the snakes rapidly adapted to the conditions and multiplied. Their venom has evolved to kill the species that were trapped with them, as well as migratory birds. 

Related: Which country has the most islands?

Snake Island is devoid of mammals, so golden lanceheads have no natural predators; their venom is intended for hunting prey, rather than for defense. Research suggests their venom is the fastest-acting of any lancehead snake (Bothrops) and five times as potent as that of a closely related species (Bothrops jararaca) that lives on the mainland, likely because catching birds requires a swift kill. 

Golden lancehead venom is fast-acting in humans, too. Bites cause symptoms ranging from local pain and swelling to nausea, intestinal bleeding, kidney failure and tissue death. Despite these risks, a few people inhabited Snake Island until the 1920s to operate a lighthouse that was built in 1909. While it's likely the last people left when the lighthouse became automated, local rumors suggest the last keeper and his family died from the bites of snakes that slinked into their home through a window. 

Researchers estimate that between 2,000 and 4,000 golden lanceheads live on Snake Island. The species has not been found anywhere else in the world and is listed as critically endangered on the IUCN Red List. 

Snake Island has been protected as an area of ecological interest since 1985; only the Brazilian navy and research teams with special waivers are permitted to access the island. But poachers have also made their way to the island to catch snakes and extract their venom, which is highly prized on the black market, according to BBC Science Focus. Scientists think the number of these snakes is decreasing partly due to this illegal trade, but also due to disease and inbreeding. 

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

Snakes escape predators by playing dead — and they make their performances even more convincing by smearing themselves with their own blood and feces, scientists have discovered.

Playing possum is common in the animal kingdom. Various insects, fish, amphibians, reptiles, birds and mammals all fake their own mortality in last-ditch efforts to fool predators. This behavior is known as death feigning or thanatosis. 

In a paper published May 8 in the journal Biology Letters, researchers described how dice snakes (Natrix tessellata) take their Shakespearean theatrics to the next level. 

When confronted by a predator, the snakes expel fecal matter and musk, a putrid digestive byproduct. They then flop on their backs and feign death, and sometimes they begin bleeding from the mouth, likely in an attempt to make themselves a less-appealing meal. 

"Death feigning is a high-risk, high-reward behavior. If you feign death, you're completely helpless, so it would be nice if you have some sort of protection against just being instantly consumed," lead author Vukašin Bjelica, a biologist at the University of Belgrade, told Live Science.

Dice snakes reach maximum lengths of about 4 feet (1.2 meters) and are nonvenomous, so they have few defenses against larger mammals and birds in their native range of Europe, Asia and northern Africa. 

But by deploying this suite of behaviors — known as a defense portfolio — dice snakes can make themselves seem unappetizing. The stench of the feces and musk and the bloody drool leaking from their mouths may give the impression that the snake is a rotting carcass rather than a fresh piece of meat. 

Related: Slow-motion footage of snake attacks reveals surprise discovery about how they kill

The revulsion and confusion that this macabre display evokes in a potential predator may provide just enough time for the snake to escape or even induce the predator to abandon its efforts entirely. 

The researchers focused on a population on Golem Grad, an island in Lake Prespa, North Macedonia. This population appears to be more predisposed to thanatosis than other populations of dice snakes. 

"The dice snakes from Golem Grad are in a peculiar set of circumstances. First of all, there is an intense avian predation pressure. Second, these snakes are rather large when compared to their mainland relatives," Bjelica said. "Being big is good if you're faced off against a gape-limited predator such as some birds."

They tested 263 dice snakes on the island by handling them in ways that simulated how a predator might approach its prey — grasping, holding and stretching its body. Of these snakes, 124 smeared feces on their bodies. Twenty-eight bled from the mouth — a phenomenon called autohemorrhaging or reflex bleeding. 

Bjelica thinks that individual personalities may determine whether the snakes engage in this behavior. "Some individuals are more bold — prone to risks — or shy — less likely to engage in risky behavior," he said.

Only one juvenile snake bled from the mouth, indicating that this behavior is more common in adults, and it may be too much of a risk for smaller snakes. "Juvenile snakes are smaller than adults and can easily be consumed. This might be one of the reasons they avoid this risky display," Bjelica said.

Dice snakes that expelled feces and musk and then bled from the mouth spent less time in a death-feigning state, the researchers found. The snakes that used fecal smearing and mouth bleeding spent an average of 2 seconds less in thanatosis, which the researchers believe to be significant survival advantage.

These snakes are not the only animals known to go the extra mile when playing dead. Virginia opossums (Didelphis virginiana) may defecate and drool while feigning death, indicating that this evolutionary strategy has proven useful across the spectrum of animal life.

Scientists in India have discovered the fossilized remains of an ancient snake that may be the largest known serpent to ever live.

The supersized serpent may have measured 50 feet (15 meters) long — surpassing the current record-holder Titanoboa by around 6.5 feet (2 m).

The newly identified species, named Vasuki Indicus, takes its genus name from the mythical king of serpents in Hinduism, which is often depicted wrapped around the neck of one of Hinduism's main deities, Shiva.

A total of 27 fossilized vertebrae from the enormous snake were unearthed at the Panandhro Lignite Mine in Gujarat state. The fossils date to around 47 million years ago, during the Eocene epoch (56 million to 33.9 million years ago). The authors think the fossils came from a fully grown adult.

The team estimated the serpent's total body length using the width of the snake's spine bones and found that V. indicus could have ranged from between 36 feet and 50 feet (11 and 15 m) long, although they acknowledge there may be a possible error associated with their estimate. They published their findings Thursday (April 18) in the journal Scientific Reports.

Related: Snakes are built to evolve at incredible speeds, and scientists aren't sure why

The researchers used two methods to come up with possible ranges for V. indicus' body length. Both used present-day snakes to determine the relationship between the width of a snake's vertebrae and its length — but they differed in the datasets they used.

One used data from modern snakes in the Boidae family, which includes boas and pythons and contains the largest snakes alive today. The other dataset used all types of living snakes.

"Vasuki belongs to an extinct family of snakes, distantly related to pythons and anacondas, and so when you're using existing snakes to estimate body length, there may be uncertainties," study co-author Debajit Datta, a postdoctoral researcher at the Indian Institute of Technology Roorkee, told Live Science.

The upper end of their estimations would make V. indicus even bigger than Titanoboa cerrejonensis, the biggest snake ever discovered until now, which lived around 60 million years ago and was unearthed in 2002 in northeastern Colombia.

V. indicus belongs to a group of snakes known as Madtsoiidae, which first appeared in the late Cretaceous period (100.5 million to 66 million years ago), in South America, Africa, India, Australia and Southern Europe.

Looking at the sites where ribs would attach to the vertebrae, the researchers think V. indicus had a broad, cylindrical body and mostly lived on land. Aquatic snakes, in comparison, tend to have very flat, streamline bodies.

Due to its large size, the researchers say the snake was likely an ambush predator, subduing its prey by constriction, similar to modern-day anacondas.

The scientists estimate that V. indicus thrived in a warm climate with an average of around 82 degrees Fahrenheit (28 degrees Celsius) — significantly warmer than the present day.

"There are still many things we don't know about Vasuki. We don't know about its muscles, how it used them or what it ate," Datta said.

Sunil Bajpai, study co-author and a vertebrate paleontologist at IIT Roorkee, said the team hopes to have the fossils analyzed for their carbon and oxygen content, which may reveal more about the snake's diet.

First-of-its-kind footage captures a rare tug-of-war battle between two venomous coral snakes competing for wormlike prey. 

In the video, the two red-tailed coral snakes (Micrurus mipartitus) wrestle over a slimy caecilian — a limbless tropical amphibian — pulling back and forth to win the meal. This is the first time that food theft, known as kleptoparasitism, has been recorded within the venomous snake family Elapidae in the wild.

The observation was documented in a study published March 22 in the journal Herpetozoa.

"It was breathtaking because I knew it was a unique observation!" lead author Henrik Bringsøe, a herpetologist and previous chairman for the Nordic Herpetological Society, who witnessed the behavior, told Live Science in an email. 

Related: Giant ball of Burmese pythons having sex discovered in Florida Everglades in record-breaking catch

Herpetologists stumbled upon the rare behavior while searching for amphibians and reptiles in the rainforest of western Colombia at nightfall. The battle had already begun when they arrived.

"We suddenly saw the two coral snakes in an energetic competition or combat for the prey which was a rather unusual amphibian called a caecilian looking like something between a worm and a snake," Bringsøe said.

The footage shows the two coral snakes using a spinning maneuver while biting the caecilian, possibly to untwist the caecilian as it struggled to escape, according to the study.

According to the study, both snakes detected the same caecilian using chemoreception — a way of finding prey using their sense of taste and smell.  

Previous research has suggested that some caecilian species have evolved resistance to the neurotoxins in the venom of Micrurus species. Scientists think this explains why the caecilian is seemingly unaffected by the snake venom after numerous bites to its flesh.

The encounter lasted 17 minutes before the winning snake slithered off with the caecilian. "We gave highest priority to not disturb them, which might well have spoiled the value of our observations," Bringsøe said.

Kleptoparasitism is reported across the animal kingdom, but it is most commonly observed in birds. For example, gulls tend to steal freshly caught shellfish from smaller shorebirds. "In captivity, where the space available is much more limited than in the wild, kleptoparasitism may be seen fairly often if several snakes are kept together," Bringsøe said. 

However, reports of kleptoparasitism among snakes in the wild are rare and underreported. "Snakes can be very secretive and live hidden lives (as the coral snakes, in our case, do) which means that behavioral studies in the wild will be particularly difficult and time-consuming," Bringsøe said. 

Python meat is a low-effort and sustainable protein alternative that could soon slither onto our dinner plates, scientists suggest.

The researchers argue there are a plethora of benefits to farming pythons, including the snakes' ability to fast for extended periods of time, their low space and water requirements and minimal waste production. 

Due to their large body size and fast growth rates — and without legs or wings to worry about — pythons are a highly efficient source of meat. The scientists published their findings Thursday (March 14) in the journal Scientific Reports. 

"These animals are extremely good converters of food and particularly protein," study co-author Patrick Aust, a zoologist and research associate at the University of Oxford in the U.K., told ABC News. "Literally, they are specialists [at] making the most of very little."

Python farming is well-established in Asia but is yet to take off in other regions, according to the study. With current livestock production systems struggling to meet sustainability standards and growing demand, however, it may be time to consider alternatives.

Related: Enormous Burmese python killed in Florida Everglades was about to lay 60 eggs

"Over the last two decades, snake farming has expanded," the authors wrote in the study. "Reptile meat is not unlike chicken: high in protein, low in saturated fats, and with widespread aesthetic and culinary appeal."

The researchers monitored the growth rates of newborn Burmese (Python bivittatus) and reticulated  (Malayopython reticulatus) pythons at two farms — one in Thailand's Uttaradit province and the other in Ho Chi Minh City, in Vietnam. Despite receiving food only once per week, both species grew rapidly and put on up to 1.6 ounces (46 grams) per day over a period of 12 months — by which time they can be slaughtered for meat, skins and other products. Female pythons grew larger than males, likely due to natural sex differences. 

The researchers fed the pythons a variety of diets, including thawed frozen chicken, wild-caught rodents, fishmeal, chicken pellets and waste products from pork production.

Roughly a quarter of the food ingested by the snakes was converted to meat, regardless of which diet they were fed, and 82% of the snakes' body mass was edible meat by the end of the experiment. For comparison, the meat harvested from cattle generally amounts to about 63% of a cow's weight.

"In terms of food and protein conversion ratios, pythons outperform all mainstream agricultural species studied to date," the researchers wrote in the study. "Production efficiencies for pythons were higher than those reported for poultry, pork, beef, salmon, and crickets."

Pythons also maintained their body mass during periods of fasting that lasted as long as 127 consecutive days thanks to their flexible metabolism. Adult Burmese and reticulated pythons can weigh more than 220 pounds (100 kilograms) and females can produce up to 100 eggs per year, meaning they are "well suited for commercial production," according to the study. 

The researchers highlighted the potential role of python farming in controlling rodent pests and upcycling waste products from other meat industries and agri-food supply chains, if the snakes are fed a diet rich in rodents and waste protein.

The only remaining hurdle to putting python meat on dinner plates is a limited understanding of how to keep thousands of these snakes in captivity, the authors wrote — that, and "the general fear humans have toward snakes."

If you're bitten by a venomous snake, the medicine you need is antivenom. Unfortunately, antivenoms are species specific, meaning you need to have the right antivenom for the snake that bit you. Most of the time, people have no idea what species of snake has bitten them. And for some snakes, antivenoms are simply not available.

New research my colleagues and I conducted provides a significant step forward in enabling the development of an antivenom that will neutralize the effects of venom from any venomous snake: a so-called "universal antivenom".

In our paper, published in Science Translational Medicine, we describe the discovery and development of a laboratory-made antibody that can neutralize a neurotoxin (a toxin that acts on the nervous system) found in the venom of many types of snake around the world.

Venomous snakes kill as many as 138,000 people each year, with many more survivors suffering from life-changing injuries and mental trauma. Children and farmers make up the bulk of the victims.

The active ingredients in antivenoms are anti-toxin antibodies. They are made by injecting horses with small quantities of snake venom and harvesting the antibodies. This method of making antivenom has remained the same for over a century — and it has substantial drawbacks.

In addition to antivenoms being species specific, they are also not very potent, so you need lots of antivenom to neutralize the venom from a bite.

Also, because antivenoms are made in horses, you are highly likely to experience severe side-effects when administered, as your body’s immune system will detect and react to the "foreign" horse antibodies circulating in your bloodstream.

Antibodies that are made in the laboratory using genetically modified cells are routinely used in humans to treat cancers and immune disorders. A long-held hope is that the technology used to produce these antibodies can be used to make antivenom and eventually replace traditional antivenoms, thereby solving many of the issues current antivenoms face.

The antibodies in lab-made antivenoms could be "humanized", a process that tricks your immune system into thinking foreign antibodies are your own antibodies. This might reduce the rate of severe side-effects that are commonly encountered with horse-derived antivenoms.

Paralysis and death avoided

One of the most important families of toxins in snake venoms are neurotoxins.

These toxins prevent nerve signals from travelling from your brain to your muscles, paralyzing them. This includes paralyzing the muscles that inflate and deflate your lungs, so prey and human victims quickly stop breathing and die.

These neurotoxins are in the venoms of some of the world's most deadly snakes, including the African black mamba, the Asian monocled cobra and king cobra, and the deadly kraits of the Indian subcontinent.

In our research, we describe the discovery and development of a lab-made humanised antibody that can neutralize key venom neurotoxins from diverse snakes from diverse regions.

The lab-made antibody is called 95Mat5 and was discovered after examining 50 billion unique antibodies to find ones capable of not only recognizing the neurotoxin in the venoms of many species but also able to neutralize its deadly effects.

When injected into mice that had received lethal doses of venom, 95Mat5 was able to prevent paralysis and death in all the venoms tested.

These results are particularly exciting as they show that generating lab-made antibodies that can broadly neutralize the effects of venoms from many species is feasible, making the development of a universal antivenom a realistic prospect.

However, 95Mat5 is a single antibody that only works against neurotoxins. As we said earlier, to make a universal antivenom you will require a handful of antibodies. This is because snake venoms don't just consist of neurotoxins.

Some snake venoms have haemotoxins, which make you bleed, and some have cytotoxins, which destroy skin and bone. To create a universal antivenom, capable of treating any bite from any snake, we still need to identify additional antibodies that can broadly and potently neutralize the other toxin types, in the same manner as 95Mat5.

We hope that once identified, these antibodies can be mixed with 95Mat5 to make an antivenom that is capable of neutralizing the venom of any snake, no matter what toxin types it possesses.

The requirement for antibodies for other venom toxins and also the need to ensure any new lab-made antivenom for effectiveness and safety in human trials means it will still take many years for a universal antivenom to become available to snakebite victims.

Other hurdles need to be overcome. These new antivenoms will probably need to be stored in a fridge to prevent loss of effectiveness, so it will need to be shown that they can be distributed in often warm regions of the world that don't have reliable electricity for refrigeration.

Lab-made antibodies are some of the most expensive drugs on the planet. While we are hopeful, it remains to be seen if lab-made antivenoms will be affordable for most snakebite victims, who are usually some of the poorest people in the world.

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

An enormous mound of Burmese pythons entwined in a 7-foot-wide (2.1 meters) mating ball was recently found in Florida's Everglades after conservationists followed several tagged males that were out looking for sex.

The mating ball contained a 14-foot-long (4.2 m) female and five males, and two additional males were found close to the aggregation, Ian Bartoszek, a wildlife biologist and science coordinator at the conservation organization Conservancy of Southwest Florida, told Live Science in an email.

"It is an impressive sight to see a large breeding aggregation of pythons in the wild," he said. "They are truly beautiful creatures and are here unfortunately as a byproduct of the pet trade."

Bartoszek and colleagues headed into the Everglades in mid-February to track down invasive Burmese pythons (Python bivittatus) at the peak of their breeding season. The Conservancy's tracking program has been running since 2013. Through the program, adult male pythons are tagged with a radio transmitter and then released as "scout snakes" to lead researchers to other pythons during the breeding season in early spring. The newfound snakes are then removed from the wild, with the primary goal of preventing breeding females from producing more offspring.

Related: Enormous Burmese python killed in Florida Everglades was about to lay 60 eggs

The captured pythons are humanely euthanized and necropsied in a lab, to collect data on their condition, breeding potential and gut contents, for example. Scout snakes, on the other hand, are left in the wild to lead the trackers to more pythons.

To date, the program has led to the removal of 1,300 pythons, with a combined weight of over 35,000 pounds (16,000 kg), from 150 square miles ( 390 square kilometers) of public and private land across southwestern Florida.

During the February snake-finding expedition, the team came across three mating aggregations. The first mating ball found included a 16-foot-long (4.9 m) female weighing 125 pounds (57 kilogram) and two males, with their tagged snake hiding nearby.

"We didn't have a bag with us large enough for the female so we had to transport her in a kayak and get her back to the field truck after hiking her out of the woods over our shoulders," Bartoszek said.

The second mating ball with six snakes was the biggest encountered on the trip, with the team finding a "pile of pythons" entwined, he added. In addition, a snake scout was found mating with a 13-foot-long (4 m) female.

In total, they captured 11 pythons with a combined weight of more than 500 pounds (227 kg).

"This was a record for us for the amount and total weight of snakes collected in a single day over ten years of the program," Bartoszek said. The scout snakes were left in the wild to slither another day.

Burmese pythons are thought to have been introduced to the Everglades at some point before 1985 when they were released into the wild via the pet trade. Their numbers grew slowly until the 1990s, when they skyrocketed. Since these generalist predators gained a foothold, they have decimated populations of native species, including mammals and birds, and thus disrupted this fragile ecosystem.

"It often feels like a CSI wildlife crime scene in our lab during necropsies and we often see first-hand how they are getting so large," Bartoszek said. "In fact 2 of the 3 females captured during the previously mentioned mating aggregations had the remains of white tailed deer inside.

"We see the remains of white-tailed deer inside of pythons often and it should sound an alarm," he said. "The Burmese python is the invasive animal issue of our time for native wildlife in Florida."

Snakes have a supercharged evolutionary clock that enables them to adapt at far faster rates than other reptiles, scientists have discovered. This ability has helped them become evolutionary "winners" and spread across the planet.

"Snakes are like the Big Bang 'singularity' in cosmology — a dramatic expansion of diversity in species and their ecologies, linked to some event that might have occurred early in the evolutionary history of snakes," lead author Pascal Title, a evolutionary macroecologist at Stony Brook University in New York, said in a statement.

In a new study, published Thursday (Feb. 22) in the journal Science, the researchers investigated what makes animal groups evolutionary winners — in particular, why certain groups are able to diversify into more species and appear better at surviving events like mass extinctions — study author Daniel Rabosky, an evolutionary biology at the University of Michigan, whose research focuses on macroevolution, told Live Science in an email. 

The scientists looked at squamates, the order of reptiles that includes snakes and lizards and includes over 11,000 species. In this group, snakes, in particular, are widely diverse — the roughly 4,000 known snake species vary from venomous sea snakes, giant constrictors and hooded cobras to tiny threadsnakes that burrow to feed on ants and termites. 

Related: The biggest snake in the world (and 9 other giant serpents)

To find out why snakes are such an evolutionary success story, the researchers carried out a huge study of the genomes of almost 1,000 snakes and lizards. They also examined dietary preferences by looking at the stomach contents of over 60,000 museum specimens and field observations. With this data, they built up a comprehensive evolutionary tree of bodily and dietary changes in the group over time. They then used mathematical and statistical models to look at how snakes and lizards evolved. 

Their findings suggest that snakes underwent several evolutionary explosions and evolved three times faster than lizards, in terms of diversity. After likely first emerging about 128 million years ago, there was a huge burst at some point between then and 70 million years ago, during the Cretaceous period (145 million to 66 million years ago), and another major pulse after the dinosaurs went extinct at the end of the Cretaceous. 

This fast rate of evolution continues to this day, the team's models show. 

"Compared to lizards, they have changed relatively rapidly, and they've continued to do so through time," Rabosky said. "So we would also say that the continued 'evolutionary explosion' of snakes is still ongoing today and appears partly driven by the fact that the rate of evolution — their 'evolutionary clock' so to speak — is just ticking a lot faster than many other groups of animals. This fast-ticking-evolutionary-clock is really important because it lets snakes evolve new traits quickly that can take advantage of opportunities that come up." 

Snakes' evolutionary flexibility enables them to change their body shape and diets "very quickly," he said. The initial "singularity" that led to snakes' success appears to have started with them developing limbless bodies, flexible skulls and advanced chemical-detection systems. 

These changes enabled them to target a huge array of prey, providing the framework for individual species to develop and specialize. Previous research published in 2021 shows the diversity in their diets exploded after the dinosaurs went extinct, with snakes quickly evolving new adaptations to take advantage of the new world they found themselves in — a dinosaur-less world in which mammals were starting to gain a foothold. 

But why snakes ended up with a fast evolutionary clock in the first place is still a mystery. "This is the big question for us," Rabosky said. "We can’t really explain this yet … But this is the nature of science, right? Usually, solving a mystery goes hand-in-hand with raising new questions that you have to answer." 

And snakes are likely continuing to adapt and evolve in super-quick time. "This is obviously speculation, but we don’t see any signs that the rapid evolution of snakes is slowing down," Rabosky said. "Snakes seem to be continuing to evolve new ways of life, and I have every expectation that this would continue into the future."

The green anaconda has long been considered one of the Amazon's most formidable and mysterious animals. Our new research upends scientific understanding of this magnificent creature, revealing it is actually two genetically different species. The surprising finding opens a new chapter in conservation of this top jungle predator.

Green anacondas are the world's heaviest snakes, and among the longest. Predominantly found in rivers and wetlands in South America, they are renowned for their lightning speed and ability to asphyxiate huge prey then swallow them whole.

My colleagues and I were shocked to discover significant genetic differences between the two anaconda species. Given the reptile is such a large vertebrate, it's remarkable this difference has slipped under the radar until now.

Conservation strategies for green anacondas must now be reassessed, to help each unique species cope with threats such as climate change, habitat degradation and pollution. The findings also show the urgent need to better understand the diversity of Earth's animal and plant species before it's too late.

An impressive apex predator

Historically, four anaconda species have been recognised, including green anacondas (also known as giant anacondas).

Green anacondas are true behemoths of the reptile world. The largest females can grow to more than seven meters long and weigh more than 250 kilograms.

The snakes are well-adapted to a life lived mostly in water. Their nostrils and eyes are on top of their head, so they can see and breathe while the rest of their body is submerged. Anacondas are olive-coloured with large black spots, enabling them to blend in with their surroundings.

The snakes inhabit the lush, intricate waterways of South America's Amazon and Orinoco basins. They are known for their stealth, patience and surprising agility. The buoyancy of the water supports the animal's substantial bulk and enables it to move easily and leap out to ambush prey as large as capybaras (giant rodents), caimans (reptiles from the alligator family) and deer.

Green anacondas are not venomous. Instead they take down prey using their large, flexible jaws then crush it with their strong bodies, before swallowing it.

As apex predators, green anacondas are vital to maintaining balance in their ecosystems. This role extends beyond their hunting. Their very presence alters the behaviour of a wide range of other species, influencing where and how they forage, breed and migrate.

Anacondas are highly sensitive to environmental change. Healthy anaconda populations indicate vibrant ecosystems, with ample food resources and clean water. Declining anaconda numbers may be harbingers of environmental distress. So knowing which anaconda species exist, and monitoring their numbers, is crucial.

To date, there has been little research into genetic differences between anaconda species. Our research aimed to close that knowledge gap.

Untangling anaconda genes

We studied representative samples from all anaconda species throughout their distribution, across nine countries.

Our project spanned almost 20 years. Crucial pieces of the puzzle came from samples we collected on a 2022 expedition to the Bameno region of Baihuaeri Waorani Territory in the Ecuadorian Amazon. We took this trip at the invitation of, and in collaboration with, Waorani leader Penti Baihua. Actor Will Smith also joined the expedition, as part of a series he is filming for National Geographic.

We surveyed anacondas from various locations throughout their ranges in South America. Conditions were difficult. We paddled up muddy rivers and slogged through swamps. The heat was relentless and swarms of insects were omnipresent.

We collected data such as habitat type and location, and rainfall patterns. We also collected tissue and/or blood from each specimen and analysed them back in the lab. This revealed the green anaconda, formerly believed to be a single species, is actually two genetically distinct species.

The first is the known species, Eunectes murinus, which lives in Perú, Bolivia, French Guiana and Brazil. We have given it the common name "southern green anaconda". The second, newly identified species is Eunectes akayima or "northern green anaconda", which is found in Ecuador, Colombia, Venezuela, Trinidad, Guyana, Suriname and French Guiana.

We also identified the period in time where the green anaconda diverged into two species: almost 10 million years ago.

The two species of green anaconda look almost identical, and no obvious geographical barrier exists to separate them. But their level of genetic divergence — 5.5% — is staggering. By comparison, the genetic difference between humans and apes is about 2%.

Preserving the web of life

Our research has peeled back a layer of the mystery surrounding green anacondas. This discovery has significant implications for the conservation of these species — particularly for the newly identified northern green anaconda.

Until now, the two species have been managed as a single entity. But each may have different ecological niches and ranges, and face different threats.

Tailored conservation strategies must be devised to safeguard the future of both species. This may include new legal protections and initiatives to protect habitat. It may also involve measures to mitigate the harm caused by climate change, deforestation and pollution — such as devastating effects of oil spills on aquatic habitats.

Our research is also a reminder of the complexities involved in biodiversity conservation. When species go unrecognised, they can slip through the cracks of conservation programs. By incorporating genetic taxonomy into conservation planning, we can better preserve Earth's intricate web of life — both the species we know today, and those yet to be discovered.

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

Discover the fascinating world of camouflage and masterful mimicry in this gallery of hidden animals. From elusive snow leopards to tiny mantises, these animals of all shapes and sizes can blend seamlessly into their environments. 

Walking leaves

Just a photo of leaves? Take a closer look …

Found across Asia, three leaf insects (Cryptophyllium westwoodii) cling to the wooden branches of a plant. 

Hidden beneath the sand

The venomous horned rattlesnake (Crotalus cerastes) is a master of disguise. Hidden deep within the sand, it waits patiently for its prey to come near before striking. It is sometimes called the sidewinder rattlesnake because it throws its body sideways across the ripples in the sand to move around very quickly.

Somewhere in this photo, a golden eye can be seen peeking out from beneath the sand.

Pygmy seahorse

Hippocampus bargibanti was the first pygmy seahorse described in the world. As the name suggests, pygmy seahorses are incredibly tiny, only growing to 0.8 inch (2 centimeters) in length. They seamlessly blend into the coral in the ocean. 

A family of mallard ducks

Time for a tricky one. Amid this rocky shore, a mother mallard (Anas platyrhynchos) and her three baby chicks are camouflaged perfectly against the terrain.

Almost mistaken as another group of rocks, they sit just left of the two big rocks in the center frame.

Color-changing antics

Chameleons are famous for their camouflage. Their ability to change color is controlled primarily by their top skin layer, which can change its structure to manipulate how light is reflected.

In this photo, a high-casqued chameleon (Trioceros hoehnelii) hides among the lichen- and moss-covered tree bark. 

Lurking in the coral

The most venomous fish in the world is the stonefish (Synanceia verrucosa), and it has a disturbing resemblance to coral-covered rocks in shallow waters.

Look closely, and you may be able to see a face emerge from the coral. 

Peering through the tall grass

A wildcat lurks through the tall grass in this photo. Can you spot it?

Bobcats (Lynx rufus) are quiet hunters that use their dull, dense coats to blend into their surroundings before they pounce at prey. 

Himalayan tahr

In the Himalayas and certain parts of New Zealand, large hoofed and goat-like Himalayan tahrs (Hemitragus jemlahicus) live on the mountain slopes and hillsides. 

Up high in the trees

Spotted coats help leopards (Panthera pardus) blend into tall grass or tree canopies.

Buried for protection

While they rest and digest their food, stingrays use their wings to bury themselves in the sand to hide from predators.

Look closely to spot a pointed tail protruding from the sand.

Wild waved sphinx moth

Hiding in plain sight, the waved sphinx moth (Ceratomia undulosa) rests on the bark of a tree.  

Amidst the rocky terrain

This photo was taken in France's Mercantour National Park after mountain goats were spotted moving across the mountainside. 

Hidden in the tundra

Another challenge: Spot the camouflaged hare, which is nearly invisible among the moss, lichen and rocks in the tundra.  

White-tailed deer

Behind the trees is a group of white-tailed deer (Odocoileus virginianus), which can be found throughout most of North America. 

Although their coats change color from reddish-brown to gray in the winter for camouflage, these deer depend on their excellent hearing and speed to escape large predators such as wolves, bears and mountain lions.

How many do you see?

Hidden woodland songbird

Rightly named a brown creeper (Certhia americana), this tiny, woodland songbird is a common-but-elusive critter in Central America. These birds spiral up and down large trees, looking for loose bark to nest behind. Their brown and speckled bodies make it difficult to find them when they are perched on a tree. 

Concealed in the moors

The mottled brown and tan plumage of this wild mallard helps it blend into its surroundings, providing perfect concealment amid the grass of the moors. 

Mimicking caterpillar

Many insects use camouflage to mimic objects or animals. Many species of caterpillar in the family Geometridae use camouflage to mimic twigs on plants. Some copy not only the shape, but also the color of a twig. 

Mysterious nightjar

Is it a snake? A lizard? No, it's a bird.

The common pauraque (Nyctidromus albicollis) is a type of nightjar. These medium-size birds have pointed wings and long tails and are active only at night.

During the day, this bird sleeps on the open ground, and its unique coloration allows it to remain hidden.

Cloaked stalking tiger

You may have been quick to spot the tiger prowling in the background of this photo, but if you were a deer, it would not have been that easy.

In the wild, tigers prey on many types of deer. Deer's vision is limited to colors on a spectrum between green and blue. This means they don't see the predator as orange, so the tiger would be green and thus hidden in the dried grass. 

Brightly colored crab spider

Camouflaged on the tops of flower heads, the goldenrod crab spider (Misumena vatia) waits, with its legs held out to its sides, for pollinating insects to ambush. These spiders' cryptic colors allow them to hide in white or yellow flowers. 

Devil scorpionfish

The devil scorpionfish (Scorpaenopsis diabolus) is a venomous and well-camouflaged marine fish found in the Indo-Pacific region. It possesses spines with toxic venom for defense and relies on its unique appearance to ambush prey.

This species is known for its intricate patterns and colors, making it a fascinating-yet-dangerous inhabitant of coral reefs.

Seamlessly hidden common sole

The common sole (Solea solea) is a flatfish that lives in the North Atlantic Ocean and Mediterranean Sea. Its upper side mimics the seafloor, blending in with the sand or gravel, while the underside is white to avoid detection from below while it swims. This adaptation helps the sole avoid predators and ambush prey effectively. 

Protection for new born chicks

The pied avocet (Recurvirostra avosetta) is a shorebird that boasts a striking black-and-white pattern and an upturned bill, which the bird uses to sift through sand to find small invertebrates in shallow pools at low tide. 

The chicks have silver-gray feathers, which provide effective camouflage in the avocet's marshy habitat. This plumage helps the bird blend in with its surroundings, offering protection from potential predators. As the chicks grow, their black-and-white coloring will gradually appear.

Amidst the rocky terrain

Let's zoom out for this one.

Known for its shifty nature and distinctive coat, the snow leopard (Panthera uncia) inhabits the steep, rugged terrain of Central and South Asia. The snow leopard has a thick coat, wide paws and a long tail that it uses for balance while climbing mountains.

The king of camouflage

Nestled against the coral sits an octopus, the king of camouflage. These alien-like creatures can not only change the color of their bodies but also mimic textures. 

An unwelcome tagalong

Be careful where you step!

At first glance, this photo may seem like a standard image taken during a hike — but the fallen leaves mask an unwelcome tagalong.

Viperidae is a family of snakes, commonly known as vipers, that are venomous, nocturnal and found all over the world. Some are very colorful. Others, like the one in this photo, are dark and marbled, allowing the snakes to blend into the scattered shadows on the forest floor. 

Insect or plant?

Stick insects are known for their mimicry of twigs or branches. Found in the tropics, these critters have elongated bodies and legs, making the insects tricky to spot among the plants. 

Perched high in the trees

The Eastern screech owl (Megascops asio), native to North America, is a small bird known for its trill-like calls. With a height of around 6 to 10 inches (16 to 25 cm), it comes in two colors: red and gray. These nocturnal hunters often inhabit wooded areas and are cavity nesters, using abandoned nests or tree hollows. 

Amongst the rocks and boulders

You have eagle eyes if you can spot the small bird in this photo.

Oenanthe melanura, commonly known as the blackstart, grows to a maximum height of 5.5 inches (14 cm). It is found in rocky habitats and arid landscapes across Southern Europe and North Africa, and often nests in rock crevices. 

The floral mimicry of an orchid mantis

Orchid mantises (Hymenopus coronatus) look and behave like flowers. This behavior involves swaying from side to side to resemble a flower blowing in the wind. They use this technique for both hunting and hiding. 

A stealthy stalker hidden in the tall grass

The fastest mammal in the world is also one of the best-camouflaged animals. The spots on cheetahs (Acinonyx jubatus) help camouflage their bodies by offsetting shadows against the tall grasses in their habitats. While camouflaged, they can stalk their prey without being seen and protect their cubs from predators. 

Eurasian bittern amongst the reeds

The Eurasian bittern (Botaurus stellaris) is a wading bird known for its elusiveness and camouflaged plumage. Found in wetlands across Europe and Asia, it is known for its booming calls during breeding season. 

Frosty disguise of an arctic hare

The Arctic hare (Lepus arcticus) is adapted to harsh Arctic climates. Known for its white fur in the winter and dark fur in the summer, it has large hind legs and padded feet that hold its weight above thick snow for running swiftly at up to 37 mph (60 km/h).

Mealy amazon parrots

How many can you see?

A group of southern mealy Amazon parrots (Amazona farinosa) is found high in a subtropical forest in Ecuador. 

Long-spinnered bark spider

Can you find the eight-legged trickster hidden in this photo?

This spider is known as a long-spinnered bark spider or two-tailed spider, part of the genus Hersilia. It is named after its large spinnerets, the silk-spinning organ on the back of its abdomen. 

Video footage of the moment snakes launch themselves at their prey reveals that the reptiles are either "strikers" or "lungers" — and the difference between the two is rooted in their teeth, new research has found.

Strikers attack at lightning speed from above, impaling their prey with needlelike teeth at the front of their lower jaw before wrapping their head over and around to inject venom with their fangs, or to squeeze the animal to death. These snakes include many boas, such as boa constrictors (Boa constrictor), and pythons.

Kingsnakes, pine snakes (Pituophis melanoleucus) and some ground boas are lungers, according to Bill Ryerson, a senior lecturer in anatomy at Cornell University's College of Veterinary Medicine. Lungers "strike more slowly and don't open their mouths as wide," Ryerson, who presented the new research at the annual meeting of the Society for Integrative and Comparative Biology earlier this month, told Live Science in an email. "They make contact with both jaws simultaneously." 

Herpetologists have long focused their attention on snakes' fangs, which are teeth modified to inject venom, but they have largely ignored the rest of the teeth. "We just assumed they are all the same and will not tell us much about the evolution of snakes," Ryerson said.

But Ryerson's work suggests otherwise. While a snake's other teeth may not catch our eyes quite the same as its fangs do, they are still important in how snakes evolved to attack and kill, he said.

Related: Watch 2 giant, highly venomous black mambas fighting in someone's backyard

"I've done quite a bit of work in the last few years on the striking behavior of snakes and I began to wonder how those teeth function in the ultrafast striking, especially for the non-venomous snakes like our boas and pythons," Ryerson said. While peering into the mouths of dozens of preserved specimens, Ryerson found that some snakes, such as boa constrictors, have narrow, upright teeth in their front lower jaw, while others, including kingsnakes, have stouter, curved teeth.

Then, Ryerson used X-rays to scan the jaws and teeth of almost 70 snakes from 13 species, Science reported. Using high-speed video, he also filmed snakes charging at dead rodents that he wiggled in front of them to analyze the snakes' striking behavior. 

His observations neatly sorted into two categories, Ryerson said. Strikers showed more variation in the size and shape of their teeth, which became shorter, broader and more curved toward the throat. Lungers, on the other hand, had broad, curved teeth all along their upper and lower jaws. 

The fact that snakes have different dentitions wasn't so surprising, as it was "unlikely that all the teeth would be the same across all species," Ryerson said. "However, I was surprised by how well the shape of the teeth corresponded to the strike behavior."

Countless factors influence the anatomy and behavior of snakes, so Ryerson expected a blurrier picture, he said. "It's really made me excited to try and sample more broadly to see how well this pattern will hold up," he added.

More specialized snake species, such as those that live in trees or underground, may not fit into either category, Ryerson said.

Australia hosts a dizzying array of venomous creatures — including spiders, snakes, jellyfish, octopuses, ants, bees and even platypuses.

But why do so many Australian animals wield this bioweapon?

Many of these beasties predate Australia as a continent. But it's another story with venomous snakes, which arrived after the continent arose.

Australia became a separate landmass about 100 million years ago when it split from the southern supercontinent Gondwana, said Kevin Arbuckle, an associate professor of evolutionary bioscience at Swansea University in the U.K. The venomous insect lineage is two to three times older than this separation, he told Live Science in an email.

Put another way, some already venomous species simply got stuck on Australia when it became an isolated landmass. Venomous arthropods there include trap-jaw ants (genus Odontomachus), which can inflict a painful bite; but these insects also live in other tropical and subtropical regions around the world, not just Australia. Similarly, Australian bulldog ants (genus Myrmecia), which can simultaneously sting and bite, are among the deadliest ants in the world and have reportedly killed three people since 1936, according to Guinness World Records. These venomous ant lineages were already on Gondwana at the time of separation and stayed there once Australia became its own continent.

As for spiders, funnel-web spiders (genera Hadronyche and Atrax) are the only exclusively Australian ones that can kill humans with a venomous bite, Arbuckle said. Male Sydney funnel-web spiders (Atrax robustus) are thought to have killed 13 people, although no human deaths have been recorded since antivenom was introduced in 1981, according to the Australian Museum. An Australian species of widow spider, the redback (Latrodectus hasselti), can also kill with a venomous bite. Their ancestors, too, predate Australia as a separate continent.

Likewise, venomous cephalopods, including squid, octopus and cuttlefish, have existed for up to 300 million years. They've lived in the surrounding waters for eras before Australia existed on its own.

Related: What's the difference between poison and venom?

Another part of this answer stretches back 60 million years to "an accident of history," according to Michael Lee, a professor of evolutionary biology at the South Australian Museum and Flinders University. Back then, continental drift pushed Australia over the frigid South Pole, which wiped out most of its reptiles. When the continent slowly drifted northward, it warmed up and attracted reptiles once again. By chance, 40 million years after this "accident," the first snakes colonized the continent — and they happened to be from the venomous front-fanged Elapidae family, which includes cobras, mambas, coral snakes and taipans. They became the land's snake ancestors, which then evolved into more venomous snakes.

Of Australia's 220 snake species, 145 are venomous, Lee told Live Science via email. These deadly serpents account for 65% of Australia's snake population, though only about 15% of the world's snakes are venomous.

As for jellyfish, every species is venomous. They also date back over 500 million years and have been floating through the ocean since before Australia existed. While deadly box jellyfish (such as Carukia barnesi) and Portuguese man o' war (Physalia physalis) reside in Australian waters, Arbuckle emphasized that these creatures populate tropical and subtropical waters, not just those Down Under. They're a "not particularly Australian phenomenon," he said. Rather, Australia's coastline fosters an ecosystem fit for these creatures.

Enumerating just how many venomous creatures Australia hosts is difficult.

"The short answer is lots, and probably more than [we] think," Dieter Hochuli, an ecology professor at the University of Sydney, told Live Science in an email.

Aside from snakes, however, Arbuckle argued Australia's venomous fauna are actually well within typical range. "Contrary to popular belief, Australia isn't particularly abundant or diverse in venomous invertebrates," he told Live Science. "Australia has a remarkably enduring and prominent image as the home of highly venomous animals, yet for the most part this is overstated."

He wondered if part of this belief stems from the continent's "scientific capital" and "excellent infrastructure" for public health and medical care.

"Its venomous animal diversity is not unusual at all for a largely tropical area," Arbuckle said.

Archaeologists in Mexico have discovered a 1,000-year-old statue of a Maya warrior in the basement of a temple at Chichén Itzá in the Yucatán Peninsula.

The statue depicts a warrior wearing a helmet shaped like a serpent with its jaws open, as well as a feathered headdress, Mexico's National Institute of Anthropology and History (INAH) said in a translated statement. The statue is 13 inches (33 centimeters) tall and 11 inches (28 cm) wide, and aside from a crack, it's in good shape, according to the statement. The head may have once been part of a larger sculptural design.

Chichén Itzá flourished between the ninth and 13th centuries and covers more than 740 acres (300 hectares). At the center of the site, a pyramid known as El Castillo (The Castle) rises 100 feet (30 meters) high. The site has many temples, as well as a massive ball court and an astronomical observatory.

Related: Palatial 1,500-year-old Maya structure unearthed in Mexico

The site is a popular tourist destination, and over the past few years, the INAH has been modifying and building new visitor centers and museums, as well as a new train line, known as the "Tren Maya," near the site, the statement said. The statue was found during archaeological work accompanying that railway construction.

A wealth of other archaeological finds have been made during this construction work, including about 660 human burials, over 1 million ceramic fragments, the remains of numerous architectural structures, and a variety of other artifacts, the statement said.

The second-largest Burmese python ever discovered in South Florida has been captured after give people sat on the enormous snake, which was found stretched out across a road in the Big Cypress National Preserve.

Initially, the python-hunters thought the female snake was an alligator due to its size. "It was more than a snake, it was a monster," conservationist Mike Elfenbein told CBS News.

After realizing it was a Burmese python (Python bivittatus), one of the men, Carter Gavlock, grabbed the snake's tail to constrain the animal, but it dragged him away. "That was a big mistake because the snake damn near took him into the canal. There was nothing he could do to stop it," Elfenbein said. Eventually, five men had to sit on the snake to capture it.

The python weighed 198 pounds (90 kilograms) and measured 17.2 feet (5.2 meters), making it the second-heaviest ever caught in Florida. The heaviest Burmese python was captured in 2022 and weighed 215 pounds (98 kg). 

Related: Burmese pythons are helping rats take over Florida's Everglades — and that could help spread disease

Burmese pythons are native to southeast Asia and considered an invasive species in Florida. These snakes have a large breeding population within and around the Everglades and have proved devastating to native wildlife, despite efforts over recent years to reduce their numbers.

Pythons are hard to detect, which makes population estimates difficult, but tens of thousands of the snakes are thought to live in Florida. Research from the U.S. Geological Survey published this year found that more than 10,000 Burmese pythons have been captured in the state in the past five years.

Nobody knows exactly how the species first arrived in the state. In the 1970s, the animals were popular in the pet trade and may have been released both accidentally and intentionally. Burmese pythons began to thrive in Florida in the 1980s and 1990s and have spread across nearly all of southern Florida.

Limiting the spread of Burmese pythons is a key goal of the Florida Fish and Wildlife Commission, and it is legal for people to hunt and kill them humanely. 

Earlier this year, a 16-foot-long (5 m) Burmese python was caught and killed in the Florida Everglades with a clutch of 60 eggs that were days from being laid.

An earthquake last year revealed a big surprise beneath a law school in modern-day Mexico City: a giant, colorful snakehead from the Aztec Empire.

The snakehead dates back more than 500 years, to when the Aztecs controlled the area, which at the time was part of the flourishing capital of Tenochtitlan. The sculpture was discovered after a magnitude-7.6 earthquake struck Mexico City on Sept. 19, 2022; the seismic event caused damage and changes in the topography, revealing the snakehead beneath a building that was part of a law school at the National Autonomous University of Mexico, Mexico's National Institute of Anthropology and History (INAH) said in a Spanish-language statement.

The Aztecs built temples and pyramids and worshipped a number of deities, including Quetzalcoatl, who was often depicted as a snake. However, it's unclear if this sculpture depicts him, the archaeologists said.

The sculpted snake is 5.9 feet (1.8 meters) long, 2.8 feet (0.85 m) wide and 3.3 feet (1 m) high, and it weighs about 1.3 tons (1.2 metric tons), the INAH said. Several colors — including red, blue, black and white — are preserved on the sculpture.

Related: Stone human 'effigies' unearthed at Aztec temple in Mexico City were likely looted in battle and offered to the gods

Color was preserved on about 80% of the sculpture's surface. To keep it preserved, an INAH team lifted the snakehead out of the ground with a crane and constructed a humidity chamber around the sculpture. This chamber allows the sculpture to lose humidity gradually, with its color being preserved, María Barajas Rocha, a conservationist with the INAH who worked extensively on the sculpture, said in the statement.

While other snakehead sculptures have been found at Tenochtitlan, this one is particularly important for its preserved colors, said Erika Robles Cortés, an archaeologist with the INAH.

"Thanks to the context in which this piece was discovered, but above all, thanks to the stupendous intervention of the restorers-conservators led by Maria Barajas, it has been possible to stabilize the colors for its preservation in almost all the sculpture, which is extremely important, because the colors have helped us to conceive pre-Hispanic art from another perspective," Robles Cortés told Live Science in an email.

The sculpture's "sheer size is impressive, as well as its artistry," but the survival of the colors is remarkable, said Frances Berdan, a professor emeritus of anthropology at California State University, San Bernardino who was not involved with the excavation. "The survival of black, white, red, yellow, and blue paints is particularly interesting — one gains a good image of the visual impact of such sculptures as they were arrayed about the city center," Berdan told Live Science in an email.

In addition to its preserved colors, the snakehead's size is notable, said Bertrand Lobjois, an associate professor of humanities at the University of Monterrey in Mexico who is not involved in the excavation. The "first time I saw this serpent head, I was dazzled by its dimensions," he said in an email.

Lobjois also praised the conservation work that allowed the colors to survive, noting that "the conservation process allows us to appreciate the naturalistic approach of figuration" the Aztec artists used.

This work is ongoing and will continue at the site into next year.

How much can the written records of ancient civilizations tell us about the animals they lived alongside? Our latest research, based on the venomous snakes described in an ancient Egyptian papyrus, suggests more than you might think. A much more diverse range of snakes than we'd imagined lived in the land of the pharaohs — which also explains why these Egyptian authors were so preoccupied with treating snakebites!

Like cave paintings, texts from early in recorded history often describe wild animals the writers knew. They can provide some remarkable details, but identifying the species involved can still be hard. For instance, the ancient Egyptian document called the Brooklyn Papyrus, dating back to around 660-330 B.C. but likely a copy of a much older document, lists different kinds of snake known at the time, the effects of their bites, and their treatment.

As well as the symptoms of the bite, the papyrus also describes the deity associated with the snake, or whose intervention might save the patient. The bite of the "great snake of Apophis" (a god who took the form of a snake), for example, was described as causing rapid death. Readers were also warned that this snake had not the usual two fangs but four, still a rare feature for a snake today.

The venomous snakes described in the Brooklyn Papyrus are diverse: 37 species are listed, of which the descriptions for 13 have been lost. Today, the area of ancient Egypt is home to far fewer species. This has led to much speculation among researchers as to which species are being described.

The four-fanged snake

For the great snake of Apophis, no reasonable contender currently lives within ancient Egypt's borders. Like most of the venomous snakes that cause the majority of the world's snakebite deaths, the vipers and cobras now found in Egypt have just two fangs, one in each upper jaw bone. In snakes, the jaw bones on the two sides are separated and move independently, unlike in mammals.

The nearest modern snake that often has four fangs is the boomslang (Disopholidus typus) from the sub-Saharan African savannas, now only found more than 400 miles (650 km) south of present-day Egypt. Its venom can make the victim bleed from every orifice and cause a lethal brain hemorrhage. Could the snake of Apophis be an early, detailed description of a boomslang? And if so, how did the ancient Egyptians encounter a snake that now lives so far south of their borders?

To find out, our masters student Elysha McBride used a statistical model called climate niche modeling to explore how the ranges of various African and Levantine (eastern Mediterranean) snakes have changed through time.

Niche modeling reconstructs the conditions in which a species lives, and identifies parts of the planet that offer similar conditions. Once the model has been taught to recognize places that are suitable today, we can add in maps of past climate conditions. It then produces a map showing all the places where that species might have been able to live in the past.

On the trail of ancient snakes

Our study shows the much more humid climates of early ancient Egypt would have supported many snakes that don't live there today. We focused on 10 species from the African tropics, the Maghreb region of north Africa and the Middle East that might match the papyrus's descriptions. These include some of Africa's most notorious venomous snakes such as the black mamba, puff adder and boomslang.

We found that nine of our ten species could probably once have lived in ancient Egypt. Many could have occupied the southern and southeastern parts of the country as it then was — modern northern Sudan and the Red Sea coast. Others might have lived in the fertile, vegetated Nile valley or along the northern coast. For instance, boomslangs might have lived along the Red Sea coast in places that 4,000 years ago would have been part of Egypt.

Similarly, one entry of the Brooklyn Papyrus describes a snake "patterned like a quail" that "hisses like a goldsmith's bellows." The puff adder (Bitis arietans) would fit this description, but currently lives only south of Khartoum in Sudan and in northern Eritrea. Again, our models suggest that this species' range would once have extended much further north.

Since the period we modeled, a lot has changed. Drying of the climate and desertification had set in about 4,200 years ago, but perhaps not uniformly. In the Nile valley and along the coast, for instance, farming and irrigation might have slowed the drying and allowed many species to persist into historical times. This implies that many more venomous snakes we only know from elsewhere might have been in Egypt at the time of the pharaohs.

Our study shows how enlightening it can be when we combine ancient texts with modern technology. Even a fanciful or imprecise ancient description can be highly informative. Modeling modern species' ancient ranges can teach us a lot about how our ancestors' ecosystems changed as a result of environmental change. We can use this information to understand the impact of their interactions with the wildlife around them.

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

A herpetologist in France has captured a remarkable photo of a snake choking as it attempted to eat a fish the size of its own head.

While many snake species eat fish — and many can open their jaws wide enough to gulp down large prey — the fish species in this case was invasive in this part of Europe. The scientist who spotted it says that the encounter should prompt more research into the relationship between fish-eating snakes and invasive species.

Nicolas Fuento, a herpetologist at the nonprofit League for the Protection of Birds in France, encountered the viperine snake (Natrix maura) at Lac de Carcès in southeastern France. At first he thought the snake was simply trying to eat the fish. But then he realized the snake was struggling.

"The snake showed unusual spasmodic movements in an apparent attempt to expel the fish, which appeared to be lodged in the snake's [esophagus]," he and a colleague wrote in a research note describing the incident, published Sept. 10 in the journal Herpetology Notes.

Related: Watch slime-covered penis mushroom that smells like rotting flesh grow and decay in mesmerizing time-lapse

Fuento got an intern to hold the snake while he tried to remove the fish, but the fish's spines along its back were stuck in the snake's esophagus. So to get it out, he gently pushed the fish into the snake's mouth to dislodge the spines, "as if I were removing a hook from a fish's mouth," he told Live Science in an email.

Once relieved of the fish, the snake did not appear to be injured and slithered away under a rock, he said.

With the fish out of the snake's mouth, Fuento identified it as a ruffe (Gymnocephalus cernua). Ruffes are small freshwater fish native to parts of Europe and Asia, but the species has been introduced to North America and other parts of Europe, including France — and their tough and spiny dorsal fins could make them difficult for some predators to swallow.

Viperine snakes spend most of their time in and around water, eating mostly fish, and their native range overlaps with ruffes in some regions, according to the paper. But the paper also noted that ruffes are an invasive species in Mediterranean wetlands, where viperine snakes are rare and declining.

That decline has been caused by several threats, including river pollution, wetland destruction and urbanization, Fuento told Live Science. His paper noted that the ruffe's introduction could be another potential threat to the local snake population — although the actual impact of the invasive fish on the snakes has not been studied.

The paper points to other instances where fish-eating snakes in Europe, including viperine snakes, have died after eating invasive fish such as largemouth bass (Micropterus salmoides), brown bullheads (Ameiurus nebulosus) and common sunfish (Lepomis gibbosus).

But snakes can also die after mishaps while eating native fish too, the paper noted, and some snakes seem to have the ability to avoid "harmful alien fishes."

"The goal of this article is to quote a new case of mortality by exotic fish," Fuento said. "And we hope that may lead to further research."

Snakes are known for gulping down truly gargantuan meals. However, one species of serpent outpaces them all, consuming the largest prey relative to its size of any known snake — and it's not the python.

Known as the Gans' egg-eater (Dasypeltis gansi), this skinny, nonvenomous African snake has a gape so big that it can swallow spherical bird eggs whole despite its diminutive size, which tops out at about 40 inches (102 centimeters) in length. Its ability to dine on prey much larger than itself comes from the stretchy skin that connects the snake's left and right lower jawbones, allowing it to open its maw exceedingly wide, according to a study published Aug. 8 in the Journal of Zoology.

"They seem to be the world record holder for the size of their gape and their overall size," study author Bruce Jayne, a biologist and professor in the Department of Biological Sciences at the University of Cincinnati, told Live Science. "Their ability is even more extreme than Burmese pythons'."

In fact, the Gans' egg-eater can devour prey three to four times larger than snakes that are classified as "generalists," such as the black rat snake (Pantherophis obsoletus), whose diet, in addition to eggs, includes things like rodents and amphibians, according to a statement. 

Related: The biggest snake in the world (and 9 other giant serpents)

Jayne put the Gans' egg-eater's egg-swallowing skills to the test — even capturing its eating abilities on video — to investigate whether it had the largest gape relative to its size.

In the lab, Jayne fed a Gans' egg-eater a quail egg. After swallowing it whole, the snake contorted its spine to crack the egg, eventually regurgitating only the broken eggshell. (The entire process lasted 15 to 30 minutes.)

The fact that teeth are "nearly absent in the species" proves beneficial, since it "helps the liquid contents of the egg not to be expelled" as the snake swallows it, Jayne said.

"Swallowing a relatively benign object that is hard and smooth is difficult to do," Jayne said. "Having teeth would cause [the egg's contents] to splash out [of its mouth] if it's punctured by needle-like structures like teeth."

This isn't the first time Jayne has tested snakes' gape sizes. Last year, he studied how wide Burmese pythons (Python bivittatus) could open their mouths. He found that they, too, have an impressive ability to dine on larger prey; in the wild, they've been known to swallow deer whole.

While that's no doubt impressive, a Gans' egg-eater is capable of consuming prey with a cross-sectional area that's more than twice that of a Burmese python of similar weight, according to the study.

Jayne said this "superpower" is a means for survival, since most bird eggs are "stout" and "spherical," like Ping-Pong balls, whereas mice and rats are typically more elongated, the former proving more challenging for other snake species with smaller mouths. The Gans' egg-eater's extreme gape evolved so that the snake could specialize in eating prey that has "a modest amount of mass per cross-sectional area," according to the statement. 

"One of the benefits of eating eggs is that they don't fight back," Jayne said. "D. gansi has a prey resource that is immobile."

Editor's note: This article has been corrected to say mice and rats are more elongated than bird eggs.

The sound of a rattlesnake's rattle is perhaps the most frightening sound you could hear on a hike. But how and why do these snakes make this iconic noise?

"Everything tells us that they rattle to alert predators," David Pfennig, a professor of biology at the University of North Carolina at Chapel Hill, told Live Science. Rattlesnakes may seem like fearsome creatures, but they are not at the top of the food chain. When a predator or a beast that could trample it — like a coyote or a bison, respectively — approaches, the rattle warns the predator to stay away or else it might get the fangs. 

However, scientists didn't always know this. According to Pfennig, until the 1950s, there was a lot of debate about what the rattle was actually used for. Some thought it could be used to attract mates.

Instead, the rattle works as a so-called aposematic signal, meaning that instead of being quiet or camouflaged, the animal has a trait that makes it stand out to its predators. It may sound counterintuitive, but many animals use aposematic signals. Poison dart frogs are brightly colored, for example, and bees have distinctive yellow and black stripes. But being threateningly conspicuous doesn't work if the threat is empty. Behind the dart frog's bright colors is an incredibly potent poison, behind the bee's stripes is a stinger, and behind the rattlesnake's rattle is a set of venomous fangs. Predators that can learn to associate the signal with the threat live to see another day.

Related: What are the world's deadliest snakes?

In 2016, Bradley Allf, then an undergraduate student in Pfennig's lab, and colleagues investigated the evolution of the rattlesnake's rattle. They found that the ancestors of rattlesnakes likely shook their tails when under threat long before rattles appeared on rattlesnakes. 

Allf looked at the tail-shaking behavior of 56 snake species and found that even though rattlesnakes were the only ones in the study to have rattles, most snakes in the study rapidly flick their tails when threatened. What's more, snakes more closely related to rattlesnakes tended to shake their tails faster and more frequently than species more distantly related to rattlesnakes. By the time rattles evolved, the snakes already knew how to use them.

"Usually when snakes or other reptiles shed, they get rid of their old skin and replace it with new skin from underneath," Boris Chagnaud, a professor in the Faculty of Natural Sciences at the University of Graz in Austria, told Live Science. "It's the same for the rattlesnakes, except that at the tail end, one piece of skin remains attached, which means that every time they shed, they get one more keratinous segment on the rattle, which is the part that generates the sound." (Keratin is a protein that's also found in our hair, nails and skin.)

These loosely attached dead skin segments are hollow and filled with air. Instead of rattling pieces of keratin inside the rattle like a maraca, the segments click together to make the famous rattling noise. And that rattling behavior is more sophisticated than it might seem.

In 2021, Chagnaud was part of a team that discovered that rattlesnakes create a clever auditory illusion with their rattles. They found that rattlesnakes begin rattling their tails at rather low frequencies — at least at first. But if the predator — or, in the case of their experiment, a human volunteer approaching a virtual snake — began to move toward the snake, the rattling would become progressively faster.

It's like the audio alarm in a "car that beeps faster as you approach a wall," Chagnaud said.

But here's the trick: If the predator continues to approach, the snake's rattling frequency will suddenly increase by 20 or 30 hertz, creating the illusion that the snake is now much closer than it actually is. 

For an animal that can't even hear its own rattle, rattlesnakes sure make effective use of that sound. 

On Aug. 4, hunters in southern Florida will begin a cull of Burmese pythons as part of an annual competition to try and keep the invasive snakes' population in check.

Burmese pythons (Python bivittatus) are native to southeast Asia, where they slink through thick jungles, grasslands and swamps. But these snakes — which can grow to be more than 18 feet (5.5 meters) long — have also established an invasive population in southern Florida that has decimated local ecosystems, with the snakes devouring prey as large as deer and alligators.

Researchers aren't sure exactly how the animals gained a foothold in the state, but one theory is that the invasive snakes got their start in 1992 when Hurricane Andrew destroyed a reptile breeding facility near Miami, setting Burmese pythons loose across the Sunshine State. 

But many experts say this is likely an oversimplification of the pythons' origin story.

In 1992, Andrew slammed into the Miami area as a Category 5 storm, quickly becoming one of the most destructive hurricanes in American history. More than 15 feet (4.5 m) of storm surge flooded the coast and over 10 inches (25 centimeters) of rain dropped in some areas, with wind gusts of about 167 mph (269 kph).

Related: Gruesome video reveals the moment a 5-foot alligator corpse was cut from the gut of a dead python

According to The New Yorker, a warehouse filled with reptiles in Homestead, Florida, just south of Miami, was destroyed during the storm — and one official told the magazine that he remembered seeing hundreds of Burmese pythons in that warehouse. When the storm destroyed the building, those pythons could have gotten loose in the swampy environs of southeast Florida.

Many wild animals did get loose during Andrew's landfall, and some newspapers reported sightings of large snakes in the storm's aftermath. But individual Burmese pythons have reportedly been spotted in the Everglades since at least 1979, with unconfirmed reports throughout the 1980s, according to a 2023 report. 

The snakes were not commonly sighted in southern Florida until at least 1995. While that's three years after Andrew, the timing and geography of the python invasion don't fit with the storm theory, scientists say.

From 1995 to 2000, 11 pythons were sighted or captured in the southwestern part of Everglades National Park — miles away from the destroyed reptile facility in Homestead. "When the population started to grow initially, in the 1990s, most of it was 20 miles [32 km] away from that facility," Dan Simberloff, an ecologist at the University of Tennessee, told Live Science.

It wasn't until after the turn of the millennium that the snakes routinely showed up in the Miami area, near where the warehouse once stood.

Based on this geography and the population's growth rates, a 2011 study concluded that the simplest explanation for the Burmese python invasion is that a few individual snakes were released into the southern Everglades sometime before 1985, with the population growing slowly until the 1990s, before skyrocketing upward. 

The 2023 report noted that a second, separate introduction of Burmese pythons may have occurred in southwest Florida, closer to Naples.

"While some believe Hurricane Andrew in 1992 caused the python problem, Burmese pythons had been detected here prior to that hurricane, as early as 1979. Several introduction events likely occurred in south Florida," a spokesperson for the Florida Fish and Wildlife Conservation Commission told Live Science via email.

This doesn't necessarily mean that Hurricane Andrew didn't contribute to the snakes' spread, however — it is possible that some snakes escaped from the pet trade during the storm and joined the feral population, experts said.

"If it was a multiple choice question as to how did Burmese pythons get into the south Florida ecosystem and (A) was 'Escaped Pet,' (B) was 'Intentionally Released,' and (C) was 'Meteorological Disturbances' — I would circle (D): 'All of the Above,'" Ian Bartoszek, an environmental scientist with the Conservancy of Southwest Florida, told Live Science.

Simberloff said that over the past two decades, research has shown that many invasive species that were thought to be a result of a single introduction were actually introduced in their new habitats multiple times. This includes the brown anole (Anolis sagrei), another reptile invasive to Florida.

About 17,000 Burmese pythons were imported to the United States between 1970 and 1995 for the pet trade — and with that many pythons coming in, it's entirely plausible that a few will be released by their owners.

"People can get tired of having a huge snake," Simberloff said.

Bartosek, who kept Burmese pythons as pets growing up in Florida, also noted that the snakes are "escape artists" — and it's possible that some pet snakes could have snuck out of homes and into the warm, prey-filled habitats of southern Florida. It is now mostly illegal to keep the species as a pet in the state.

The population of wild Burmese pythons in Florida is unknown, but estimates suggest there could be hundreds of thousands out there. Last year's Python Challenge saw 231 snakes removed from the Everglades, and while initiatives like this are helpful in controlling the population, eradication is currently out of the question. 

"Eradication of the entire population across the landscape is not possible with any existing tools, whether applied singly or in combination," the 2023 report said.

A huge Burmese python has been caught in Florida with a clutch of 60 eggs that were "just days from being laid." 

Hunter Mike Kimmel captured and killed the 16-foot-long (5 meters) snake in the Everglades, where the invasive species has been wreaking havoc on local ecosystems for decades. 

"A python this size can eat anything in the Everglades, as I've proven with the multiple adult alligators I've rescued from being eaten by pythons (3 separate times)." Kimmel wrote in an Instagram post after the catch.

Burmese pythons (Python bivittatus) are native to Southeast Asia, where they are considered endangered in many regions as a result of hunting and habitat loss. They were introduced to Florida's Everglades via the exotic pet trade and quickly gained a foothold throughout the 1980s and 1990s, feasting on native populations such as rabbits, opossums, bobcats and even alligators.

Related: Burmese pythons are helping rats take over Florida's Everglades — and that could help spread disease

Limiting the spread of Burmese pythons is a key goal of the Florida Fish and Wildlife Commission, and it is legal for people to hunt and kill them humanely. It is unclear how many of these snakes now live in the Everglades, but the population is thought to number in the tens of thousands. Since 2000, over 17,000 have been removed from the wild.

One of the reasons the population is difficult to control is the number of offspring they produce. Burmese pythons mate in spring, with each sexually mature female laying up to 100 eggs about three months after mating. After the eggs are laid, the female coils around them to incubate them for six to eight weeks, until they are ready to hatch. A study published 2016 found the number of Burmese python eggs that go on to successfully hatch was 77%.

In 2022, researchers caught the biggest Burmese python ever found in the Everglades — an 18-foot-long (5.5 m) behemoth weighing 215 pounds (98 kilograms). It carried 122 egg follicles — spherical structures that mature into eggs after fertilization. 

And in April this year, a team led by the U.S. Geological Survey caught a python that had laid 96 eggs in one go — setting a new record for Florida, New Scientist reported. 

Two huge, highly venomous black mambas — both over 8 feet (2.4 meters) long — have been filmed in a fierce wrestling match in a person's backyard. 

The males fought for over 30 minutes in Queensburgh, South Africa. The pair were filmed in a twisted embrace as they attempted to pull each other to the ground. 

The bigger snake, which was 8.5 feet (2.6 m) long, tried to pin down the neck of the smaller, 8.2-foot-long (2.5 m) snake, Nick Evans, a snake rescuer who uploaded the video to Facebook, wrote in the description. This happened three times before the smaller snake "surrendered" and moved away. The exhausted black mambas were then caught and released away from people. Evans wrote they were likely fighting over a female, as it is currently their mating season.

The bruising encounter raises an intriguing question: Why don't black mambas (Dendroaspis polylepis) bite each other when they fight? 

"Male mambas don't bite each other. They wrestle till one surrenders," Evans wrote.

Black mambas are one of the most  venomous species of snake on Earth. These snakes have a "notorious reputation" for being Africa's deadliest snake, where they are found in the eastern and southern regions of the continent, John Dunbar, an Irish Research Council postdoctoral fellow at the Venom Systems lab at the University of Galway in Ireland, said.

Related: Gruesome video reveals the moment a 5-foot alligator corpse was cut from the gut of a dead python

Their venom targets the connection between their prey's nerves and muscles. It can rapidly paralyze and kill a human in 20 minutes. However, Dunbar told Live Science that after handling these snakes to extract venom, he has found them to be "shy, nervous snakes" that would only strike a human if they felt startled or threatened.

"Venom is a precious resource reserved for catch[ing] prey and for defense," he said. 

Dunbar said the behavior seen in the video is known as "plaiting combat," which typically takes place in the presence of a female. The name comes from how the snakes will "plait" their bodies around each other in an attempt to dominate their opponent and win the female's approval. 

"Rather than simply biting and subduing [their opponent] with a fatal dose of neurotoxic venom, the aim is purely to win by [forcing] submission," Dunbar said. "[I]t's a demonstration of stamina and physical strength, not chemical warfare."

Snakes also possess immunity towards their own species' venom. Mild exposure to a snake's own venom, during activities like mating or feeding, can generate a mild immunity response, where a snake's antibodies neutralize the toxins. These same antibodies help protect it against being bitten by another member of the same species. 

However, Dunbar said snakes may not be completely immune and can occasionally succumb to the toxic effects of their own species' venom, especially in high enough doses.

"It's complicated, and probably why the males avoid biting during these combat rituals, as strength and stamina are a more appropriate measure for a female to judge their success by," he said. "The losing male usually leaves with no injuries, perhaps just a dent in his pride, while the winner will have secured mating access to the female."

Editors note: We have removed an incorrect reference to the snake's weight.

For the first time ever, scientists have created genetically modified snakes. The CRISPR-edited reptiles are providing new insight into how corn snakes (Pantherophis guttatus) develop their precisely patterned scales.

Much like feathers on birds or hairs on mammals, snake scales are the result of placodes — small, thickened structures on the skin that develop at the embryonic level, according to a new study published Wednesday (June 14) in the journal Sciences Advances.  

But unlike most other species including mice, where the placodes are random, a snake's placodes develop in a highly organized fashion, laying out the positioning of every single scale. Rather, the spatial organization of these placodes follows a  pattern in nature first explained by mathematician Alan Turing, the researchers added.

Scientists from Geneva wanted to know exactly how and why these "near-perfect hexagonal pattern[s]" developed on the dorsal scales located on the snakes' backs and flanks, but not on the ventral scales that form as a single row on the animals' underbellies.

The researchers found that an embryo's ventral scales develop first and align with the position of somites — blocks of cells that determine the location of the vertebrae, ribs, muscles and dermis of the skin. Once the ventral scales are established, two separate "waves" of placodes develop, traveling toward each other. 

The waves meet laterally, creating the tidy hexagonal patterns that are the hallmark of a snake's skin, according to a statement.

Related: Scientists changed scales on chicken feet to feathers by tweaking a single gene

"To confirm our work, we used computer simulations and received similar results," lead author Athanasia Tzika, a postdoctoral fellow in the Department of Genetics and Evolution at the University of Geneva, told Live Science. "This is surprising because the pathway is essential for proper development of skin appendages in birds, reptiles and mammals."

Tzika pointed to lizards with a mutated EDA gene, which were previously studied in her university's lab, as an example of a reptile that never developed scales.

This led researchers to create the world's first genetically modified snakes. Using CRISPR-Cas9, which edits genes by severing the DNA and letting the natural DNA repair itself, Tzika and her team successfully created "mutant" snakes that lacked dorsal-lateral (hexagonal) scales, but still had ventral scales. 

She said that this proved that the scales aren't "self-organizing" and occur "without a functional canonical EDA pathway."

In total, the scientists created four corn snakes, all of which are currently two years of age and "are doing well," Tzika said.

"The animals we produced are exactly the same as the naturally occurring snakes; we were able to reproduce the same phenotype," Tzika said. 

She said they plan to conduct another round of CRISPR edits on the genetically modified snakes in two years, once they reach sexual maturity, "to see if the mutation will transmit to the next generation."

Burmese pythons are inadvertently helping rats dominate parts of the Everglades in Florida by wiping out their traditional predators, researchers have found. The rise in rodents could further disrupt an already fragile ecosystem and increase the risk of disease to humans. 

The first Burmese python (Python bivittatus) was found in Everglades National Park in 1979, and numbers skyrocketed throughout the 1980s and 1990s. There are now tens of thousands of the snakes living in the Everglades, and over the last 40 years they have decimated native populations, including bobcats, rabbits and foxes. 

But some smaller mammals appear unaffected by the presence of Burmese pythons, including the cotton rat (Sigmodon hispidus). To find out what impact pythons are having on this species, researchers caught 115 rats and fitted them with transmitters — 34 were in an area known to have a low population of pythons, while 81 were in an area with a high python population. 

They tracked the rats every 48 hours, and recorded the predator involved when any were found dead. In cases where the corpses had likely been swallowed, the team analyzed scat and regurgitated remains for rat DNA. 

Related: Gruesome video reveals the moment a 5-foot alligator corpse was cut from the gut of a dead python

The team’s findings, published May 17 in the Journal of Mammalogy, showed that rat death rates were similar in both areas. Though pythons killed six of the tagged cotton rats in the high python population area, they did not have a significant impact on the overall rat population.

But because pythons have had a devastating effect on the populations of other, larger mammals, such as bobcats and foxes, this has left an ecosystem opening for the rats to take over.

As a result, in areas where pythons are pervasive, cotton rats "now dominate the community," study author Robert A McCleery, an associate professor of wildlife ecology and conservation at the University of Florida, told Live Science in an email. 

The collapse of large and medium-sized mammal populations in the Everglades has impacted important ecosystem processes, such as nutrient cycling and scavenging. Rabbits, for example, acted as a keystone species for seed dispersal. 

Rats, the authors said, are unlikely to be able to fulfill the roles that the lost mammals played. 

Their dominance also has the potential to spread diseases to people. Cotton rats are reservoirs for viruses that can pass to humans, including the Everglades virus (EVEV) and hantaviruses. And in a 2017 study in Biology Letters, researchers found that in the absence of other mammals, mosquitoes in some parts of the Everglades are now mainly feasting on cotton rats. Diseases carried by the rats can then be passed through mosquito bites to humans. 

The study focused on a species of mosquito — Culex cedecei  — that tends to stay away from urban areas, but another species, Culex panocossa, has also been found in Florida — and this species survives in cities. 

Nathan Burkett-Cadena, the study’s lead author and associate professor of entomology at the University of Florida,  said C. panocossa has now come into contact with cotton rats, and this could lead to "increased risk of arbovirus [viruses spread by insect vectors] infection for people living in south Florida," he told Live Science. EVEV is one of these viruses, symptoms for which include fever, severe headache, muscle pain and in rare cases, brain swelling. 

An extremely rare and potentially deadly albino cobra had to be removed from a house in India after the white snake slithered in during a severe rainstorm.

Neighbors spotted the pale cobra climbing out of fast flowing water on the ground and into a passageway beside the house in Coimbatore in Tamil Nadu state, southern India, on May 3. Experts from the Wildlife and Nature Conservation Trust (WNCT) later arrived to safely capture the snake, which was then released into the wild.

The 5-foot-long (1.5 meters) snake was identified as an albino Indian cobra (Naja naja), WNCT representatives wrote on Facebook. The species, which are also known as the spectacled cobra, is considered one of the "big four" snake species that are responsible for the most snakebite cases in India.

Albinism is a genetic condition that prevents animals from producing the pigment melanin, which gives color to their skin, fur, feathers or scales. It is recessive, meaning both parents must possess the gene and pass it onto their offspring. Albino animals also lack pigment in their irises, meaning that they have pink or red eyes, which results in reduced vision or total blindness; moreover, their skin is highly susceptible to sunburns.

Related: 7 strange snake stories from 2022

For most animals, albinism can be a death sentence. Their white color makes them stand out to predators, meaning many die as juveniles in the wild. But the Coimbatore cobra's size suggests it is fully grown and has not been overly affected by its condition. 

However, albinism isn't always a disadvantage, at least for some snakes. In a study published in February 2022 in the journal Zoology, researchers used fake snakes to test whether white or albino snakes were at a higher risk of predation from birds than normal colored individuals. The results suggested that albinism did not increase the rate of predation, likely because their discoloration confused the birds, which use the snakes' skin patterns to identify them as prey. 

Safely capturing the snake was important because the species are known to be highly venomous. "Their venom can cause paralysis and even death if not treated promptly," WNCT representatives wrote. "It is crucial to handle these snakes with great care and expertise, as any mistake can lead to severe consequences."

Between 81,000 and 138,000 deaths occur in India each year due to snakebites, according to the World Health Organization.

Cobras can also deliver dry bites, which do not contain any venom. In November 2022, an 8-year-old boy in India received a dry bite from an unidentified species of cobra before biting the snake in retaliation and killing it.