How do snails change shells?

They do not. You're thinking of hermit crabs. A snail's shell starts with the calcium gained from eating its own egg, and grows with the snail for its entire lifetime. read more

Snails do NOT change thier shells. They are born with a shell, and they continue to grow it as they grow. Removal of a shell almost always causes death to a snail. It is an important part of thier body. read more

Best Answer: No, snails grow their own shells, and the shell just gets bigger as the snail grows. You are probably thinking of hermit crabs. They live in shells that used to have mollusks (sea snails) in them, and when the crab gets bigger it has to find a new, larger, empty shell and move into it. read more