Beaks are the hard, pointed structures found on the faces of birds. They are made of a protein called keratin, which is the same material that makes up human nails and hair. Beaks come in various shapes and sizes, adapted to the bird's diet and feeding habits. For example, hummingbirds have long, slender beaks for sipping nectar, while eagles have strong, hooked beaks for tearing flesh. In addition to feeding, beaks serve other important functions. Birds use their beaks for grooming, building nests, and even defending themselves. The shape and size of a bird's beak can provide insights into its behavior and ecological role, making them a key feature in the study of ornithology.