Helix (gastropod) - Ecology

Ecology

Helix snails prefer cool, damp environments, as they easily suffer moisture loss. Snails are most active at night and after rainfall. During unfavourable conditions, a snail will remain inside its shell, usually under rocks or other hiding places, to avoid being discovered by predators. In dry climates snails will naturally congregate near water sources, including artificial sources such as waste-water outlets of air conditioners.

The common garden snail (Helix aspersa) is herbivorous. These snails are able to digest most vegetation including carrots and lettuce. They also have a specialized crop of symbiotic bacteria that aid in their digestion, especially with the breakdown of the polysaccharide cellulose into simple sugars.

Many predators, both specialist and generalist, feed on snails. Some animals, such as the song thrush, break the shell of the snail by hammering it against a hard object, such as stone, in order to expose its edible insides. Other predators, such as some species of frogs, circumvent the need to break snail shells by simply swallowing the snail whole, shell and all.

Some carnivorous species of snails, such as the decollate snail and the rosy wolf snail, also prey on Helix snails. Such carnivorous snails are commercially grown and sold in order to combat pest snail species. Many of these also escape into the wild, where they prey on indigenous snails, such as the Cuban land snails of the genus Polymita, and the indigenous snails of Hawaii.