Penguins are highly social birds, and they form large colonies. Breeding colonies, or "rookeries," can include several thousand penguins. In these large groups, penguins utilize visual displays and vocal calls to do everything from identifying individuals to selecting mates. Penguins often dive and feed in groups, another sign of their social behavior.

Penguins tend to be monogamous and sometimes mate for life. Penguins will only feed their own offspring, but in some species, chicks are grouped together while the parents hunt for fish and other food.

Like most birds, penguins are big on preening. They oil their feathers from a gland near their tail. Instead of walking, running, and flying, the unique body morphology of penguins calls for alternatives. Penguins usually waddle, hop with their feet together, or "toboggan" (slide on their pectoral side).

King Penguin breeding colony. Credit Pismire.