The snail is an air breathing gastropod mollusc with an external shell. Snails are of world-wide distribution, found everywhere except the polar regions. There are many thousands of species, with more than 120 British species, some terrestrial and some aquatic living in fresh water. There are also marine snails, of which the Periwinkle is a familiar specimen. Snails vary in size from tiny, smaller than the head of a pin, to tropical species with shells more than twenty centimetres long. Snails love damp spots and are most active after rain. In continued dry weather they retire underground or to sheltered spots, close the orifice of the shell with a film or epiphragm of dried mucus, and aestivate (remain dormant) until the damp weather returns. During the winter most snails hibernate.
The great majority of snails are vegetarian, though several British species are more or less carnivorous. Some snails possess a remarkable homing instinct, the common snail (Helix aspersa) returning to the same spot to sleep for the entire course of its life unless displaced by an accident.
Almost all snails are nocturnal, only roaming during daylight in the rain. Snails travel slowly, by way of wave-like ripples in their muscular foot. The lifespan of snails varies greatly with species, most British species living between two and five years. Snails are mostly hermaphrodites, and lay eggs. The edible snail lays eggs about the size of a pea with a white chalky shell. Some large species lay eggs as large as a bird's egg.
All terrestrial snails are edible, and were widely eaten in Britain before the Industrial revolution. Research Snail
Abbreviations
Nature
Research Snail