Biology and ecology

Ecology

Snails and slugs display selective preference for moist, humid habitats (e.g., gardens, forests, wetlands, greenhouses). There are a few terrestrial species that are adapted to environments atypical of terrestrial gastropods (e.g., the snail Cernuella virgata is adapted to living in sand dunes). Snails may aestivate under unfavorable conditions, by retracting into the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
and producing a mucilaginous structure (epiphragm) in the apertureAperture:
The major opening of a shell that the body of the animal may be retracted.
(mouth) of the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
. The epiphragmEpiphragm:
Temporary mucus secretion deposited in the aperture of the shell during periods of inactivity (e.g., aestivation). (See also operculum).
will desiccate and become papery, thus sealing the apertureAperture:
The major opening of a shell that the body of the animal may be retracted.
to reduce moisture loss. Prior to aestivation, some species prefer to affix themselves to vertical structures such as the sides of buildings, grass blades, and fence posts.

Terrestrial slugs generally prefer to inhabit dark, humid places such as beneath rocks and logs on the forest floor, in leaf litter, and under tree bark during daylight. They are normally nocturnalNocturnal:
Occurring or becoming active at night.
, although they may be found wandering about during the day after it rains.

Snails and slugs feed primarily on plant material (living or dead), mushrooms, and lichens. On occasion, terrestrial slugs and snails may feed on conspecifics, other species of mollusks and their eggs, and calcareousCalcareous:
Consisting of limestone or calcium carbonate.
material (e.g., rocks, headstones).