Apart from appropriate periods when it is active, snail presents and withdraws into its shell (hibernation). To do this, it digs a hole in the ground, stays there with the shell opening placed right up and withdrawing entirely into its shell. Afterwards, it secrets a mucous film, which hardens and turns white (chalky epiphragm), also called Opercule. During hibernation all the metabolism is retarded. It lives on its reserves (it emaciates) at spring. It recovers quickly the lost reserves.