Snakes change their skin more often at a young age, when they grow quickly than in their adult state, but on average the snake changes skin two to four times a year. Snakes, while they are young, grow very quickly, and continue to grow throughout life. However, their skin does not grow together with the rest of the body. Therefore, they should periodically discard their outer cover, which is replaced by a new skin of a larger size. In addition, skin-covering snakes scales can wear out or damage.
All animals produce new cells to replace old, worn out parts of the outer cover. But snakes do not replace gradually, but immediately; this process is called molting or dropping of old skin.
When the new skin is ready, the outer layer begins to weaken. The eyes of the snake acquire a milky-blue color due to the fact that the surface layer of the eyes begins to exfoliate.
In order for the skin to begin to drop, the snake can rub its head against the stone, trying to sift the exfoliated skin off the head. Then she just crawls out of her old skin, turning her inside out, and appears in the new skin. On the new skin the scales are located exactly the same pattern as it was on the old one.