Elephants can recognize themselves in mirrors, showing they are very smart and have self-awareness.

Koalas can sleep up to 22 hours a day because their favorite food, eucalyptus leaves, takes a lot of energy to digest.

Cheetahs are the fastest land animals, running up to 113 km/h (70 mph) in short bursts.

Giraffes have the same number of neck bones as humans—just seven!—but their bones are much bigger.

Polar bears have black skin under their white, see-through hair. Their unique fur helps them stay warm in cold weather.

A group of zebras is called a "dazzle," and when they stand together, their stripes make them look confusing to predators.

Kangaroos can't walk backwards, thanks to their muscular tails and strong body structure.

Octopuses have three hearts and blue blood, which helps them survive deep in the ocean waters.

The pistol shrimp, just 2 cm long, creates a sound louder than a jet engine by snapping its claw rapidly.

Tardigrades (tiny animals) can survive in space, extreme heat, and freezing cold, and can go for more than 10 years without eating.