Some people are grossed out by slugs, but think snails are cute. Slugs and snails are both members of a class of animals called gastropods. But shells make all the difference, it seems!
Let's get up to speed on the purpose of a snail's shell. It protects and supports the soft body inside. If threatened by an enemy, a snail can pull itself into the hard shell and stay there until the danger passes. Pretty useful to carry your own fortress around! The shell is made of a mineral called calcium carbonate. As the snail grows, its shell also gets bigger to make room for its body.
Snails and slugs also belong to a group of animals called mollusks. This family includes sea creatures like clams, conchs, mussels, oysters and scallops. Mollusk shells come in different colours, shapes and sizes. Some have spines to trap food, or ridges to help the animal stick to the ocean floor. Can you tell which animals are univalves, meaning they have one-piece shells like the snail? Which ones are bivalves (two-piece shells)?