Cats have protractable claws, which they normally keep retracted in a skin sheath, under the toe pads. This prevents the claw wearing down and allows their soft and silent walking, which is important when stalking prey. Claws are made of a protein called keratin, and grow continuously. Cats scratch to keep their claws sharp and ready to use.
Cats have five toes in each of their front paws and only four in each of their hind paws. In the front paws, the innermost toes function in a similar way to the human thumbs, when grasping objects. Genetic mutations can cause polydactylyism in cats, which is a congenial anomaly that results in the appearance of extra toes.
The tough-skin pads offer protection when walking through rough terrain, but also improve traction on slippery surfaces. Pads are very sensitive, because they contain numerous nervous terminations, including pacinian corpuscules, which allow cats to feel the texture of the terrain. Cats have five pads on each front paw and only four on each of their rear paws.
Cats have sweat glands in their paws, which help them to keep the temperature balance in their bodies. These specialized glands, which are also called eccrine, are located in the pads. Felines also have sebaceous glands tucked between their foot pads, which secrete a scented oil detectable only to cats, and keep their paws moisturized.