Snails do not change their shells. The snail's shell is its own structure and will not shed or change its shell. It will grow as its body grows. The snail's shell has been growing on the body since birth. During the growth process, calcium is secreted in the hole of the shell, causing the hole to slowly expand.

When snails' shells are broken, they can also secrete calcium to repair the broken shell. The shell of a snail is very important to the snail as it can help them avoid dangers from the outside world. If the shell is peeled off forcibly, the snail may die.

Function of snail shells

1. Protect the body: Snail shells can protect the soft body and internal organs. They can not only provide shelter from wind and rain, but also avoid enemies.

2. Moisten the body: When the snail is dormant, it can secrete mucus, which can moisten the body. It hides the whole body in the shell and comes out when the temperature and humidity are suitable.

3. Help breathing: When the snail retracts into the shell, it will leave the opening of the breathing hole at the shell mouth to facilitate breathing.