How can we tell the difference between a snail and a slug?

We were hanging out in the Wonderopolis garden the other day and overheard two earthwormsnamed Larry and Moe telling jokes: Larry: What's a slug? Moe: I don't know. ... Their only other differences are in habitat and behavior, but these differences are the result of the fact that snails have shells and slugs don't. read more

Slug versus Snail comparison chart; Slug Snail; Introduction: Slug is a common name that is normally applied to any gastropod mollusk that lacks a shell, has a very reduced shell, or has a small internal shell. Snail is a common name for almost all gastropod mollusks that have coiled shells in the adult stage. read more

The original, simple answer is that snails have an external, visible shell, and slugs do not. The problem is that there are intermediate species that do have an external shell, but one that is too small for the animal to fit inside. read more

The most-noticeable difference between a snail and a slug is the slug's lack of a shell. On a snail, the shell houses and protects the visceral hump, where the snail's organs are located. A slug, on the other hand, may have an internal"shell," which is more like a calcium deposit, that helps protect the internal organs. read more