A beak is the hard, pointed mouth part of a bird, shaped perfectly for whatever that bird needs to do. An eagle's sharp, hooked beak tears meat. A hummingbird's long, thin beak reaches deep into flowers for nectar. A pelican's massive beak scoops up fish. A woodpecker's strong, chisel-like beak hammers into tree bark to find insects.

Unlike human teeth and lips, a beak is made of the same material as fingernails and grows continuously throughout a bird's life. Birds use their beaks for eating, building nests, preening feathers, fighting, and feeding their young. Some birds, like parrots, even use their beaks almost like an extra hand to help them climb.

The word also applies to similar mouth parts on other animals. Turtles and octopuses have beaks, though they look quite different from bird beaks. You might also hear people jokingly call a person's large or prominent nose a beak, though that usage can sound rude.

Scientists can often tell what a bird eats just by looking at its beak's shape and size. A finch's short, thick beak cracks seeds. A heron's long, sharp beak spears fish. Evolution shaped each beak over millions of years into a specialized tool for survival.