Vampire bats rely on amino acids from their blood diet to fuel their exercise, scientists discovered after observing the animals on tiny treadmills.

Most mammals, including humans, rely on carbohydrates and fats from their complex diets to fuel physical activity. However, vampire bats exclusively consume blood, which is very low in carbohydrates and fats but high in protein. This raises the question of whether vampire bats instead obtain most of their energy from the protein they consume — similar to bloodsucking insects.

There are three vampire bat species: the common vampire bat (Desmodus rotundus), the hairy-legged vampire bat (Diphylla ecaudata) and the white-winged vampire bat (Diaemus youngi). All are found in warm regions of the Americas, including Mexico, South America and Trinidad, according to the  Read More »

13 of the most venomous snakes on the planet

1. Inland taipan

The inland taipan is one of the most venomous snakes, according to the International Journal of Neuropharmacology, meaning just a teensy bit of its venom can kill prey (or human victims). They live tucked away in the clay crevices of Queensland and South Australia's floodplains, often within the pre-dug burrows of other animals. Living in more remote locations than the coastal taipan, the inland taipan rarely comes into contact with humans, the Australian Museum reported. When the taipan does feel threatened, the snake coils its body into a tight S-shape before darting out in one quick bite or multiple bites. A main ingredient of this venom, which sets it apart from other species, is the hyaluronidase enzyme. According to a 2020 issue of Toxins journal ( Read More »

13 of the most venomous snakes on the planet

2. Coastal taipan

You could be bitten multiple times before becoming aware of the coastal taipan (Oxyuranus scutellatus), thanks to its incredible speed, according to the Australian Museum. When threatened, this snake, which lives in the wet forests of temperate and tropical coastal regions, will lift its whole body off the ground as it jumps fangs-first with extraordinary precision and injects venom into its enemy. Before 1956, when an effective antivenom was produced, this snake's bite was nearly always fatal, according to Australian Geographic. The snake's venom contains neurotoxins, which prevent nerve transmission. Read More »

13 of the most venomous snakes on the planet

3. King cobra

The king cobra (Ophiophagus hannah) is the world's longest venomous snake, measuring up to 18 feet (5.4 m), according to the Natural History Museum in London. The snake's impressive eyesight allows it to spot a moving person from nearly 330 feet (100 m) away, according to the Smithsonian Institution. When threatened, a king cobra will use special ribs and muscles in its neck to flare out its "hood" or the skin around its head; these snakes can also lift their heads off the ground about a third of their body length, according to the San Diego Zoo. Its claim to fame is not so much the potency of its venom, but rather the amount injected into victims: Each bite delivers about 7 milliliters (about 0.24 fluid ounces) of venom, and the snake tends to attack with three or four bites in quick Read More »

13 of the most venomous snakes on the planet

5. Saw-scaled viper

The saw-scaled viper (Echis carinatus) is the smallest member of the "Big Four" in India — along with Russell's viper, the common krait (Bungarus caeruleus) and the Indian cobra (Naja naja) — thought to be responsible for the most bites and related deaths in the country. Along with their fellow vipers, the Russel's viper and the pit viper, these nondescript little reptiles may be responsible for about 58,000 deaths a year in India alone.

13 of the most venomous snakes on the planet

6. Russell's viper

It's hard to get accurate estimates, as many people who are bitten by snakes live in regions with poor medical care and never report their encounters with the deadly reptiles. But around 58,000 deaths in India are attributed to snake bites every year, and the Russell's viper (Daboia russelii) is responsible for the majority of these mortalities, according to research published March 25, 2021, in the journal PLOS Neglected Tropical Diseases. This species is considered one of the most deadly of the true vipers, researchers reported in 2021 in the journal Toxins

 

13 of the most venomous snakes on the planet

7. Eastern tiger snake

Native to the mountains and grasslands of southeast Australia, the eastern tiger snake (Notechis scutatus) is named for the yellow and black bands on its body, though not all populations sport that pattern, according to the Australian Museum. Its potent venom can cause poisoning in humans in just 15 minutes after a bite and is responsible for at least one death a year on average, the University of Adelaide reported



 

 

13 of the most venomous snakes on the planet

8. Boomslang

About 24 hours after being bitten on the thumb by a juvenile boomslang (also called a South African green tree snake), herpetologist Karl Patterson Schmidt died from internal bleeding from his eyes, lungs, kidneys, heart and brain, researchers reported in 2017 in the journal Biochimica et Biophysica Acta. The snake had been sent to Schmidt at The Field Museum in Chicago for identification. Like others in the field at the time (1890), Schmidt believed that rear-fanged snakes like the boomslang (Dispholidus typus) couldn't produce a venom dose big enough to be fatal to humans. They were wrong. Read More »

13 of the most venomous snakes on the planet

9. Fer-de-lance

A bite from a fer-de-lance (Bothrops asper) can turn a person's body tissue black as it begins to die, according to a 1984 paper published in the journal Toxicon. These pit vipers, which live in Central and South America and are between 3.9 and 8.2 feet (1.2 and 2.5 m) long and weigh up to 13 pounds (6 kg), are responsible for about half of all snakebite venom poisonings in Central America, according to a 2001 study published in the journal Toxicon.

 

13 of the most venomous snakes on the planet

11. Eastern brown snake

Eastern brown snakes are endemic to eastern Australia and are responsible for more human fatalities than any other snake species in the country. Their venom is highly potent, containing powerful toxins that can cause paralysis and internal bleeding. The initial bite is often painless, according to the Australian Museum

"They're the only snakes in the world that regularly kill people in under 15 minutes," Bryan Fry, who studies venom at the University of Queensland, told ABC News in 2024. "Even more insidiously than that is that for the first 13 minutes, you're going to feel fine." Read More »

13of the most venomous snakes on the planet

12. Common death adder

Common death adders are found across coastal areas of southern, eastern and northern Australia. They are recognizable thanks to their broad, triangular heads, short, thick bodies and thin tails. Common death adders are ambush predators and wait for prey — including frogs, lizards and birds — under leaves until they are ready to strike. 

Bites to humans are rare and normally involve a person stepping on one by accident. Their venom causes paralysis and can lead to death: Before the introduction of antivenom in the 1950s, about 60% of bites were fatal, according to the Australian Museum Read More »