The Cerith Snail is a tremendous scavenging snail that will devour the diatom algae in your aquarium. These snails will bury into the sand bed, crawl along rockwork or aquarium glass, and do much of their feeding at night. They provide this useful service -- both the eating of algae, as well as the sifting of the sand -- with little effort or care. They make a great addition to any aquarium. They can take up to a couple of days before they begin moving around. In nature, they are found in large groups and more than one can be kept in the home aquarium.Snails belong to a Class known as Gastropods, which make up the largest class of Mollusks. Snails grow by increasing their swirling body while producing a protective shell. This shell protects their soft body from predators. They will use a pad, or foot, that extends from their shell which allows them to drag their shell along. As they drag their shell often times their mouth and eyes can be seen coming out from the opening of the shell. When frightened or sleeping this opening can be protected by an operculum, which is a hard protective cover that acts like a door to the shell. Snail identification is based on the color, shape, and pattern of their shell.