Why do snakes and lizards shed their skins?
This is one of the questions we discussed on Friday at the Caraway Elementary presentations. Snakes and lizards shed the outer layer of their skins to allow for growth and to help rid themselves of skin-borne parasites. They also sometimes shed to heal damaged skin. This shedding of skin is called ecdysis, and also takes place in insects and arthropods (such as spiders and crustaceans).
As a reptile grows, it becomes too large for the outer layer of it's skin. As the new layers of skin grow beneath, a thin layer of moisture develops between them and the old outer layer. The skin takes on a dull, often bluish appearance. In snakes, the eyes become cloudy and the snake becomes almost blind. This is because even a snake's eyes are covered with scales. After several days, the old skin starts to slough off, usually starting at the nose. Snakes crawl right out of their old skins, turning them inside-out like a sock. Lizards' skins come off in patches and some lizards even eat their old skins!