Most kinds of mammals have a thick coat of hair that serves chiefly to provide warmth. Many species also have certain hairs for special uses, such as for protection or for sense functions. Among human beings, however, hair has primarily a cosmetic value. Most of the human body is covered by tiny, light-colored hairs that are barely visible.
Thick hair grows from the scalp and some other parts of the body.
However, certain areas, such as the palms of the hands and the soles of the feet, have no hair at all. In human beings, as in other mammals, hairs around the eyes and ears, and in the nose, serve a protective function. They prevent dust, insects, and other matter from entering these organs. In addition, the eyebrows decrease the amount of light reflected into the eyes. Among mammals other than human beings, a number of species have special hairs that respond to touch.