Starfish do not have brains or blood — they use filtered sea water to pump nutrients through their bodies.

Some sharks can reproduce without a mate in rare cases.

Fact #544 · Animals

Some mammals, like bats, use echolocation.

Fact #465 · Animals

Clownfish can change sex during their lifetime.

Fact #361 · Animals

Some birds can sleep while flying.

Fact #332 · Animals

A chimpanzee can use tools to solve problems.

Fact #508 · Animals

Octopuses have three hearts and blue blood.

Fact #1 · Animals

Owls can rotate their heads up to about 270 degrees.

Fact #38 · Animals

Certain species of frogs are active at night.

Fact #519 · Animals