Octopuses have three hearts — two branchial and one systemic — and the systemic heart stops when they swim.

Dragonflies can fly in all directions, including backward.

Fact #352 · Animals

Some reptiles can survive long periods without food.

Fact #501 · Animals

Certain birds build nests on cliffs for protection.

Fact #531 · Animals

Some species of octopus can change both color and texture.

Fact #343 · Animals

Certain birds can recognize themselves in mirrors.

Fact #404 · Animals

Narwhals are known for their long spiral tusks.

Fact #376 · Animals

Some insects have lifespans of only a few hours as adults.

Fact #411 · Animals

Some fish use tools to crack open shellfish.

Fact #405 · Animals