Hagfish produce enormous quantities of slime when threatened — enough to clog predators' gills instantly.

Some species of sharks must keep moving to breathe.

Fact #284 · Animals

A polar bear's fur is actually transparent.

Fact #391 · Animals

Some frogs can survive being frozen during winter.

Fact #24 · Animals

Many birds use Earth's magnetic field for navigation.

Fact #388 · Animals

Bats are the only mammals capable of sustained flight.

Fact #58 · Animals

Some sharks can sense a drop of blood from far away.

Fact #348 · Animals

A koala sleeps for many hours each day.

Fact #490 · Animals

A zebra’s stripes may help confuse predators.

Fact #500 · Animals