Snails move like worms by alternating body contractions with stretching, with a proverbially low speed (hence the term snail mail for postal services). They produce a slime in order to aid locomotion by reducing friction. The slime also reduces the snail's risk of injury and helps keep away potentially dangerous insects like ants. In winter some snail species hibernate in their shells by closing the opening with a thin shell-like plate that they build only for this use and destroy in spring. Even some slug species build a shell-like object below their upper skin.
Snails are eaten in several countries of Europe - "escargot" in France, for instance - where they are considered a delicacy.