Many people believe snails and slugs are the same species, though it’s pretty obvious they are not.
Slugs and snails actually both belong to the same class called gastropods. The name of the class comes from the Greek words gastros, meaning stomach, and podos, meaning foot. Appropriate, don’t you think?
While most gastropods live in water, snails and slugs are the only ones that can also live on the ground. The most obvious difference between these two species is that nails have shells on their back, while slugs don’t.
Other differences include habitat and behavior, but they are largely affected by the fact that snails have shells and slugs don’t. That’s why slugs can fit into narrow places and snails can’t.