Snail

The snail is a shelled land mollusk in the class Gastropoda, order Stylommatophora, closely related to slugs but distinguished by its coiled external shell into which it can withdraw completely. The brown garden snail, Cornu aspersum, is among the most widely recognized and studied land snail species worldwide.

Snails are ecologically significant as both decomposers and grazers, breaking down decaying plant matter and consuming living vegetation, algae, and fungi. Their calcium-carbonate shell, secreted by a specialized mantle organ, grows in a spiral pattern throughout the animal's life and offers protection from predators and desiccation.

As a familiar backyard animal found on nearly every continent, the snail is a common subject of general natural history and identification interest, often confused only with its shell-less relative, the slug.

• Soft body topped by a hard, coiled shell, typically brown or tan with darker spiral banding
• Two pairs of retractable tentacles: longer upper pair with eyes at the tips, shorter lower pair for touch and smell
• Muscular foot secretes mucus for locomotion, leaving a shiny trail
• Shell shape and banding pattern vary by species and can be used for identification
• Distinguished from slugs by the presence of a visible external shell into which the body can retract

Snails are found in gardens, hedgerows, woodland edges, agricultural land, and along walls and fences, favoring moist, sheltered spots with access to calcium-rich soil for shell growth. Many familiar species originated in Europe and the Mediterranean but have been introduced widely across temperate and subtropical regions.

They are most active during humid nights and after rainfall, and they seek shelter under debris, in crevices, or by sealing the shell opening with a dried mucus membrane during dry or cold periods.

Snails glide slowly on a muscular foot lubricated by mucus and feed using a radula, a ribbon-like row of tiny teeth, to scrape algae, fungi, and plant material. They are largely nocturnal and crepuscular, avoiding the desiccating effects of daytime sun and heat.

As primary consumers and decomposers, snails recycle plant material into soil nutrients and serve as prey for birds, small mammals, and ground-dwelling predators. When threatened, a snail withdraws fully into its shell and may seal the opening with mucus.

Most land snails are hermaphroditic, and after courtship and mating, adults lay clusters of small round eggs in a shallow pit dug into moist soil. Eggs hatch into miniature snails with a soft, translucent shell that hardens and grows in spiral increments as the animal matures.

Development is direct, with no larval or pupal stage, and growth continues gradually through adulthood. In temperate climates, snails often overwinter by sealing themselves into their shells, becoming active again with warmer, wetter conditions.