ANIMAL FACTS
Why Do Sea Turtles Return to the Beach Where They Were Born?
Why do sea turtles return to their birth beaches? Discover how Earth's magnetic field helps guide them home to nest after decades at sea.
Read the story →ANIMALS TOP / SCIENCE & DISCOVERY
Animal facts, explained.
From remarkable senses to unexpected survival strategies, explore what animals do, how their bodies work and why the science matters.
FIND YOUR CURIOSITY
Explore the animal world.
Follow a question into the right kind of science. Each section opens an existing collection of guides.
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Start with a good question.
ANIMAL VISIONWhy Do Reindeer Eyes Change Color?Discover an unusual Arctic adaptation in the reflective layer of a reindeer’s eye.Read the guide →
ANIMAL BIOLOGYDo Hippos Really Sweat Blood?Separate a vivid animal myth from the biology behind its skin secretion.Explore the science →
ANIMAL BEHAVIORWhy Do Pigeons Bob Their Heads?See how head movement helps stabilize a walking bird's view.Learn why →
THE READING LIBRARY
All animal facts & guides
Explore the latest articles on surprising biology, behavior and how the natural world works.
ANIMAL FACTS
Why Do Woodpeckers Peck Trees? The Real Reasons Explained
Why do woodpeckers peck trees? Discover how they find insects, build nests, communicate by drumming, and withstand repeated impacts.
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ANIMAL FACTS
Why Do Flamingos Stand on One Leg? The Science Explained
Why do flamingos stand on one leg? Discover how the posture saves heat, reduces muscle effort, and lets flamingos balance while sleeping.
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ANIMAL FACTS
Do Crocodiles Have Tongues? Why They Cannot Stick Them Out
Do crocodiles have tongues? Learn why they cannot stick them out, how their throat valves keep water away, and why some crocodiles have salt glands.
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ANIMAL FACTS
Do Seahorses Have Stomachs? How They Digest Food
Do seahorses have stomachs? Learn how seahorses digest food without a true stomach, why they eat so often, and what their unusual digestive systems do.
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ANIMAL FACTS
Do Birds Have Ears? Where Their Ears Are Hidden
Do birds have ears? Discover where bird ears are hidden, how birds hear without external ear flaps, and why owl hearing is so remarkable.
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ANIMAL FACTS
Do Spiders Have Blood? Why Spider Blood Can Be Blue
Do spiders have blood? Learn why spider hemolymph can look blue, how their hearts and open circulatory systems work, and how blood helps move their legs.
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ANIMAL FACTS
Do Earthworms Have Eyes? How They Sense Light
Do earthworms have eyes? Learn how worms detect light through their skin, why they avoid sunlight, and how they navigate underground without seeing.
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ANIMAL FACTS
Do Bats Have Tails? Why Some Bat Tails Are Hidden
Do bats have tails? Learn why some bat tails are hidden in a flight membrane, which bats have free tails, and how tails help bats fly and hunt.
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ANIMAL FACTS
Do Ants Have Lungs? How Ants Breathe Without Them
Do ants have lungs? Learn how ants breathe through spiracles and tracheal tubes, why they don't breathe through their mouths, and whether ants can drown.
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ANIMAL FACTS
Do Dolphins Have Hair? Why Baby Dolphins Have Whiskers
Do dolphins have hair? Discover why newborn dolphins have whiskers, how their skin stays smooth, and what their whisker pits can sense.
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ANIMAL FACTS
Do Octopuses Have Bones? How Their Bodies Work
Do octopuses have bones? Learn how their boneless arms work, why they have hard beaks, and how they squeeze through incredibly small spaces.
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ANIMAL FACTS
Do Starfish Have Eyes? How Sea Stars See the World
Do starfish have eyes? Discover where their eyes are located, how many eyes they have, what they can see, and how they navigate without a brain.
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ANIMAL FACTS
Do Jellyfish Have Brains? How They Survive Without One
No, jellyfish do not have brains, but they do have nervous systems. Instead of a centralized brain like those found in humans, fish, and many other animals, jellyfish possess networks of nerve cells distributed throughout their bo···
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ANIMAL FACTS
Do Penguins Have Knees? Why You Can't See Them
Yes, penguins have knees, even though you cannot normally see them. Like other birds, penguins have thighbones, knee joints, lower-leg bones, ankles, and feet. Their knees are positioned high on their bodies and are hidden beneath···
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ANIMAL FACTS
Why Do Sea Otters Hold Hands? The Real Reason
Sea otters sometimes hold hands, or more accurately paws, while resting on the ocean surface to help prevent themselves from drifting apart. However, this behavior is much less common in the wild than popular photographs and video···
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ANIMAL FACTS
Can Crabs Breathe Out of Water? How Long Can They Survive?
Yes, some crabs can breathe out of water, but their survival depends on the species and environmental conditions. Most aquatic crabs breathe through gills that absorb dissolved oxygen from water. Many shore crabs can also obtain o···
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ANIMAL FACTS
Do Sharks Have Bones? The Truth About Shark Skeletons
Do sharks have bones? Learn why shark skeletons are made of cartilage, whether sharks have backbones and ribs, and how shark fossils form.
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ANIMAL FACTS
Do Butterflies Sleep? Where They Go at Night
Do butterflies sleep at night? Discover where butterflies rest, how they sleep with their eyes open, and why some butterflies roost in groups.
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ANIMAL FACTS
Can Owls Move Their Eyes? Why They Turn Their Heads
Can owls move their eyes? Discover why owl eyes are fixed, how far owls turn their heads, and how their unusual eyes help them hunt at night.
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ANIMAL FACTS
Do Frogs Drink Water? How Frogs Stay Hydrated
Do frogs drink water through their mouths? Discover how frogs absorb water through their skin, what the drinking patch does, and how they stay hydrated.
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ANIMAL FACTS
Do Turtles Have Teeth? How They Bite Without Teeth
Do turtles have teeth? Discover how turtles bite, eat, and crush food with their beaks, plus why baby turtles have a temporary egg tooth.
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ANIMAL FACTS
Do Snakes Blink? Why Their Eyes Never Close
Can snakes blink or close their eyes? Learn why snakes have no eyelids, how their eye caps work, and how snakes sleep and shed their skin.
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ANIMAL FACTS
Green Butterfly Identification: 8 Species You May Be Seeing
See a green butterfly? Identify green hairstreaks, malachites, emerald swallowtails, tailed jays and other green butterflies by pattern, size and location.
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Animal Comparisons →Explore side-by-side animal comparisons or find more detailed science explanations.