A penguin is a flightless seabird that lives mostly in the Southern Hemisphere, often in cold regions near Antarctica. Penguins have black backs and white fronts, stubby wings they use as flippers for swimming, and a distinctive waddle when they walk on land.

Though penguins can't fly through the air, they're extraordinary swimmers. Underwater, they “fly” through the ocean using their flipper-like wings, reaching speeds up to about 22 miles per hour as they chase fish, squid, and krill. Their black-and-white coloring acts as camouflage: from above, their dark backs blend with the deep water; from below, their white bellies match the bright surface.

Different penguin species live in different places. Emperor penguins brave Antarctica's brutal winter, huddling together in temperatures that can drop to negative 40 degrees. African penguins live on beaches near Cape Town, South Africa, where the weather is much warmer. Galápagos penguins live near the equator, making them the only penguin species found in the wild that sometimes cross slightly north of it.

Penguins are also devoted parents. Emperor penguin fathers balance a single egg on their feet for two months in the Antarctic winter, keeping it warm under a fold of skin while the mother hunts at sea. When people say someone is waddling like a penguin, they mean walking with short steps and swaying from side to side, the way these charming birds move across ice and snow.