An elephant's skin is generally very tough, at 2.5 cm (1 in) thick on the back and parts of the head. The skin around the mouth and inside the ear is considerably thinner. Elephants typically have grey skin, but African elephants look brown or reddish after wallowing in coloured mud. An elephant uses mud as a sunscreen, protecting its skin from ultraviolet light. Although tough, an elephant's skin is very sensitive. Without regular mud baths to protect it from burning, insect bites and moisture loss, an elephant's skin suffers serious damage. After bathing, the elephant will usually use its trunk to blow dust onto its body and this dries into a protective crust.