What is the Difference Between Slugs and Snails?

The main difference between slugs and snails is that snails have a coiled shell, while slugs lack a shell or have a reduced internal shell. Both slugs and snails are soft-bodied animals belonging to the group of mollusks, which also includes oysters, clams, and squid. They are found throughout the world, with some species living on land, in trees, or in water.

Here are three key differences between slugs and snails:

1. Anatomy: A snail has a noticeable coiled shell, whereas a slug may have an internal shell or a reduced shell. The snail can retract into its shell for defense, and some snails can even close their shell once fully retracted.
2. Speed: Slugs tend to move more slowly than snails. The speed of a common snail is about 1 millimeter per second, or 0.002 mph. Some snail species are faster than some slug species, and vice versa.
3. Habitat: Due to the lack of a shell, slugs can maneuver and compress themselves into hiding places with very little space, such as loose bark on trees or beneath stone slabs and wooden boards. This gives them a great environmental and survival advantage compared to snails.

Both slugs and snails are herbivorous, consuming plants, and some slugs also eat dead animal material, worms, and other snails. They are preyed upon by various predators, including snakes, toads, turtles, beetles, and birds. Gardeners often consider slugs and snails to be pests, but some types of land snails are eaten by people, especially in France.

Comparative Table: Slugs vs Snails

Here is a table summarizing the differences between slugs and snails:

Both slugs and snails are gastropod mollusks and share various characteristics, such as being slow-moving, secreting mucus for movement, and having a muscular ventral foot. However, the presence of a shell in snails and its absence in slugs lead to differences in their habitat, speed, and defense mechanisms.