¹     You go out your back door and see a tiny, shiny trail on the ground. What animal made that? It was most likely made by a snail or slug. Snails and slugs are mollusks. These are animals with soft bodies. They are also invertebrates, a group of animals that do not have a backbone.
 
²     Snails and slugs have long, moist bodies. Snails live on land. Some live in freshwater. Some snails live in the ocean. Slugs, too, live on land and in water. A land snail that you might see in your yard has a coiled shell on its back. A snail can pull its body into its shell. Slugs are like snails without shells.
 
³     Snails and slugs move by creeping on a false "foot," or pseudopod (SUE duh pod) on the bottom of their bodies. Their bodies make mucous or "slime." It comes out in front of the pseudopod. It makes a slippery, moist track for the snail to move along. When the slime track dries, it makes that shiny trail you might see at your house.

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