claw

A claw is a curved, pointed keratinous structure at the end of a digit in many animals. Claws are used for grasping, climbing, digging, defense, and capturing prey. They grow from a specialized tissue at the base and are composed primarily of keratin. In some species claws can be retractable and sheathed when not in use, while in others they remain exposed.

In mammals, claws are typically curved and sharp. Cats possess retractable claws that can be hidden within the paw, aiding stealth and reducing wear. Dogs and many other mammals have non-retractable claws that wear down with use. Claws can be highly modified for specific functions, such as digging claws in moles or traction claws in various ungulates.

In birds, the term talon is often used for the large, hunting claws of raptors. Bird claws are generally not retractable and are adapted for grasping prey, perching, and climbing. The strength, curvature, and arrangement of claws vary with diet and habitat.

Reptiles and amphibians also bear claws, typically keratinous and hooked for climbing or digging. In some invertebrates, appendages called claws perform similar grasping functions, though the term is applied less consistently.

Claw health and maintenance are considerations in domesticated animals, where overgrown or damaged claws can affect gait and posture. Regular trimming and appropriate conditioning are common management practices to preserve function and comfort.