Internal organs, such as the heart, remain inside the shell. Most aquatic snails have gills, but land snails have a breathing chamber. The land snail's breathing pore can be seen as a small hole on the right side of the body, just inside of the shell. Some freshwater snails also have this breathing chamber, and so must occasionally come to the surface for air. Another hole in this region is linked to the intestines, and is used to expel wastes.
Land snails are hermaphroditic, that is, each snail has both male and female parts.
They still must mate to reproduce, however. A hole near the head is the genital orifice where the snail mates and also where it lays its eggs. Aquatic snails have both hermaphroditic and heterosexual reproduction. Most snails lay eggs. Any damage they do cause will be compensated for by fast plant growth.