Animals Wildlife 36 Random Animal Facts That May Surprise You From proposing penguins to voting bovines, here are some quirky facts. By Russell McLendon Russell McLendon Writer University of Georgia Russell McLendon is a science writer with expertise in the natural environment, humans, and wildlife. He holds degrees in journalism and environmental anthropology. Learn about our editorial process Updated April 1, 2022 Treehugger / Russell McLendon Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species Earth is home to more than one million known animal species, each one representing an ancient tome of biological trivia. Much of this random knowledge gets lost in the ether, leaving us to speculate about things like dinosaur divorce rates or amphibian dance moves. But we still catch an awful lot, providing us with plenty of interesting—if not always actionable—facts about our fellow fauna. The list below is a tribute to such trivia. From extinct penguins to newly identified wasps, these tidbits reflect the depth of our own species' curiosity about nature—and our skill in shedding new light on it. As you peruse these facts, imagine all that went into discovering each one. We embrace their randomness here, but most hail from a robust body of knowledge about the animal in question. So without further ado, here are 36 random animal facts that may interest you. Anatomy Treehugger / Russell McLendon 1. Octopuses have three hearts. One pumps blood around the body, while the other two pump it to the gills. Oh, and that blood is blue, thanks to high copper levels! 2. Owls don't have eyeballs. They have eye tubes. 3. Polar bears have black skin. This helps it to absorb heat from the sun to stay warm in an Arctic climate, and it likely protects the bear from harmful UV rays. 4. A human brain operates on about 15 watts. Abilities Treehugger / Russell McLendon 5. Butterflies can taste with their feet, using something called chemoreceptors that help them to identify plants. Females select the correct leaf on which to lay eggs by "drumming" it with her feet to release juices. 6. Animals with smaller bodies and faster metabolism see in slow motion. 7. Dogs' sense of smell is about 100,000 times stronger than humans', but they have just one-sixth our number of taste buds. 8. Reindeer eyeballs turn blue in winter to help them see at lower light levels. (They're golden-colored in summer.) No other mammals are known to have this ability. 9. A single strand of spider silk is thinner than a human hair, but also five times stronger than steel of the same width. A rope just 2 inches thick could reportedly stop a Boeing 747. Treehugger / Russell McLendon 10. The claws of a mantis shrimp can accelerate as quickly as a .22-caliber bullet. Scientists must keep them in thick plastic tanks because their punches can break glass. 11. A sea lion is the first nonhuman mammal with a proven ability to keep a beat. A female sea lion named Ronan was trained to do it by scientists, who then showed she could transfer that skill to a song with a different beat that she had not heard before. 12. Squirrels can't burp or vomit. Nor can any other rodent. This happens to be why rat poison is so effective; other mammals tend to expel any toxic substance they ingest. 13. The extinct colossus penguin stood as tall as LeBron James. 14. Honeybees can flap their wings 200 times every second. Survival and Adaptation 15. A type of "immortal" jellyfish is capable of cheating death indefinitely. 16. Cats and horses are highly susceptible to black widow venom, but dogs are relatively resistant. Sheep and rabbits are apparently immune. 17. Sharks kill fewer than 10 people per year. Humans kill about 100 million sharks per year. They should be much more scared of us than we are of them. 18. Tardigrades are extremely durable microscopic animals that exist all over Earth. They can survive any of the following: 300 degrees Fahrenheit (149 Celsius), -458 degrees F (-272 C), the vacuum of space, pressure six times stronger than the ocean floor and more than a decade without food. Behavior Treehugger / Russell McLendon 19. Wild dolphins call each other by name. They let out a unique whistle to identify each other and will respond if they hear their own call played back. 20. Young goats pick up accents from each other. This means they join humans, bats, and whales as mammals known to adjust their vocal sound to fit into a new social group. 21. Humpback whale songs spread like "cultural ripples from one population to another." 22. Elephants have a specific alarm call that means "human." Treehugger / Russell McLendon 23. There's a place on Earth where seagulls prey on right whales. They dive-bomb the calves that are coming up to breathe air and take bites of blubber out of their backs. The calves' skin is thinner than adults' and they have to come up for air more frequently, making them more exposed and vulnerable to attack. 24. Horses use facial expressions to communicate with each other. Researchers have identified 17 discrete facial movements in horses. 25. Azara's owl monkeys are more monogamous than humans. They live together as families, with two parents and offspring, for up to nine years or when one of them dies. Fathers are highly involved in caring for their young. 26. Male gentoo and Adelie penguins "propose" to females by giving them a pebble. These are precious because the penguins use them to build their nests, and they can be hard to find along the barren Antarctic shoreline. If the female accepts the pebble, the pair bonds and mates for life. Treehugger / Russell McLendon 27. Barn owls are normally monogamous, but about 25% of mated pairs "divorce." They do so if breeding is unsuccessful. 28. African buffalo herds display voting behavior, in which individuals register their travel preference by standing up, looking in one direction and then lying back down. Only adult females can vote. 29. If a honeybee keeps waggle-dancing in favor of an unpopular nesting site, other workers headbutt her to help the colony reach a consensus. 30. The bone-house wasp stuffs the walls of its nest with dead ants. Bonus Weird Animal Facts Treehugger / Russell McLendon 31. Less time separates the existence of humans and the Tyrannosaurus rex than the T-rex and the stegosaurus. 32. Animals have some unusual group names. For instance, a group of parrots is known as a pandemonium. Buffalo form an "obstinacy" and rhinoceroses a "crash." You may have heard of a "murder" of crows, but what about an "exaltation" of larks? 33. Warmer weather causes more turtles to be born female than male. 34. A supercolony of invasive Argentine ants, known as the "California large," covers 560 miles of the U.S. west coast. It's currently engaged in a turf war with a nearby supercolony in Mexico. 35. By eating pest insects, bats save the U.S. agriculture industry an estimated $3.7 to $53 billion per year. 36. Fourteen new species of dancing frogs were discovered in 2014, raising the global number of known dancing-frog species to 24.