A snake sheds its skin by secreting a chemical that lubricates the space between the old layer and the new layer of skin. The snake then splits the old skin around its head and crawls out. It uses a rough object to anchor the old skin as it does so.
Rough objects that are commonly used to assist in the shedding process are dead branches and smooth rocks. A snake sheds anywhere from a couple of times a week to once a year depending on its size, age and health. The entire shedding process lasts for several weeks. The skin begins to turn dull and gray when a snake is preparing to shed. The snake's eyes may also turn dark blue or milky during this initial period.
Snakes are uncharacteristically aggressive during this time because of their vulnerable state. They should not be handled or touched during this period because their skin is very sensitive. Snakes may also hide and stop eating. After a week, the skin turns clear once again. The snake then removes the old skin using a rough object. This entire process is called ecdysis.
A snake that retains patches of old skin after ecdysis suffers from dysecdysis, which is caused by low humidity, malnutrition, external parasites, infections, trauma, dermatitis or overhandling. Owners are advised to seek veterinarian assistance if a snake is observed to be suffering from dysecdysis.