Tube-dwelling refers to the behavior of certain organisms that live inside tubular structures. These tubes can be made of various materials, including mud, sand, or secreted substances. Tube-dwelling species often include marine animals like polychaete worms and bivalves, which create protective homes that help them avoid predators and environmental stress. These tubes serve multiple purposes, such as providing shelter and aiding in feeding. For example, some tube-dwellers extend their feeding appendages outside the tube to capture food particles from the water. This adaptation allows them to thrive in diverse habitats, from coral reefs to mudflats.