The shell of the snail can hold its entire body. The part of the snail that is held in the shell is called the spire (coiled hump) or tortillon. The shell not only protects the snail from the weather (rain, sun, wind…), but also serves as a lung, with a cavity allowing air to flow in and out or to be contained. .

The shell is made up of 99% minerals (essentially calcium carbonate) The shell grows with the snail. Once the snail reaches maturity, the outside of the shell hardens; the snail is then 'bordé' or mature. The shell of a mature snail is about one third its weight. The snail must constantly keep a balance between the water content in its tissues and the relative humidity of the environment.

In dry periods, the snail can voluntarily dehydrate to maintain this important balance. It can do the opposite in humid periods. The escargot is thus able to absorb or release water through every pore of its skin. A snail's behavior is calculated according to its surrounding environment. Below 6 C, the snail's activity slows down as the snail hibernates either by burying itself or by operculuming. Below 0 C the snail dies. The influence of light on a snail is still not well known. Depending on the snail's species, a snail's reaction to light varies. The Helix Aspersa is most active at night. rSensitive, nevertheless, to the photo-light phenomenon, the Helix Aspersa slows down its activity to less than 14 hours of light a day. The snail which is always moist doesn't like the wind which tends to dehydrate him.