Seashells are one of the many things that help to keep our oceans clean. They are used for shelter by many marine creatures, including sea turtles and octopus. They also provide cover for small fish. They are also often used in jewelry and ornaments. They are made from calcium carbonate, a mineral that is found in the mineral form calcite. The majority of shells on the beach are made from this material.
Some of the sea creatures that use shells as their home are mollusks. These are small, soft-bodied creatures that spiral around in a clockwise fashion. Some conchs use their horn to drag along the sea floor. They also use their foot to help them move along. The mantle tissue secretes proteins and minerals into the outside of the shell. Other organisms will burrow into the shell to survive.
Another group of marine creatures that use seashells as their home are hermit crabs. As they grow, these hermit crabs will pick up the larger shells to take home. They can be a nuisance to people, as they may irritate you when you try to grab them. If you are not comfortable with this, you can leave the shells alone. Other organisms will use the shells for shelter or as building materials. These include the endangered piping plover, which uses sea shells as a part of their nest. They are also used by seabirds and octopus to provide a place to hide and shelter.