FaunaHub

Snail (class Gastropoda (shelled))

InvertebrateMolluscGastropod

Garden snail (Cornu aspersum) with its coiled shell and extended eyestalks.

Garden snail (Cornu aspersum).

Image: Rosser1954, CC BY-SA 4.0, via Wikimedia Commons.

Overview

Snails are soft-bodied molluscs (gastropods) that carry a coiled shell into which they can withdraw. They are an enormous and varied group living on land, in fresh water, and in the sea — the garden snail (Cornu aspersum) is a familiar land example. A snail glides on a single muscular “foot,” leaving a trail of mucus, and senses the world with tentacles, including eyes on stalks in many land species.

Snails and their shell-less relatives, the slugs, are closely related; the main difference is the prominent external shell that snails carry.

Note: “snail” spans countless species with different habits, so general statements vary. Treat details as approximate and verify against authoritative sources.

Habitat & Range

Snails are found almost everywhere — gardens, forests, grasslands, deserts (as dormant survivors), ponds and rivers, and across the oceans from shore to deep sea. Land snails need moisture and shelter and are most active in damp, cool conditions; many seal their shells and wait out dry or cold periods.

Diet

Diets vary widely. Many land snails are herbivores or detritivores, grazing on plants, algae, fungi, and decaying matter, while some aquatic and marine snails are predators or scavengers. Snails feed using a unique structure called a radula — a ribbon covered in tiny teeth that rasps food into the mouth.

Behavior

Snails move slowly by rippling waves of muscle along the foot, lubricated by mucus. When threatened or in harsh conditions they withdraw into the shell, and many land snails can seal the opening with a mucus “door” and become dormant for long periods. Many snails are hermaphrodites, and they often have elaborate courtship.

Human Interaction & Conservation

Snails matter to people in many ways: some are garden and crop pests, others are farmed as food, certain freshwater snails are important in disease ecology, and many are valued in the pet and aquarium hobby. Some land snails are also of serious conservation concern. Consult authoritative sources for specific species.

More photos of the snail

A small garden snail crawling, tentacles extended.

Garden snail (Cornu aspersum).

Image: Matthew T Rader, CC BY-SA 4.0, via Wikimedia Commons.

Frequently Asked Questions — Snail

What is the difference between a snail and a slug?
Both are gastropod molluscs and close relatives. The main difference is the shell: snails carry a prominent external coiled shell they can withdraw into, while slugs have lost or greatly reduced the external shell. Otherwise they share the muscular foot, mucus trail, and rasping radula.
How do snails eat?
Snails feed with a radula — a flexible ribbon covered in many tiny teeth — which they use to scrape and rasp food into the mouth. Depending on the species, that food might be plants, algae, fungi, decaying matter, or even other animals.
Why do snails leave a slimy trail?
The trail is mucus the snail secretes to glide on. It reduces friction, helps the snail move over rough or dry surfaces (even upside down), and protects the soft foot. The mucus also helps retain moisture, which land snails need.
How do snails survive dry or cold weather?
Many land snails withdraw into the shell and seal the opening with dried mucus, then become dormant — waiting out heat and drought (estivation) or cold (hibernation) until conditions improve. This lets them survive periods when activity would be dangerous.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.