The term 'limpet' is a type of GASTROPOD and MOLLUSC. Gastropods are a class of invertebrates that includes snails, slugs, and sea hares, while molluscs are a phylum of invertebrates that includes octopuses, squids, and clams. Limpets are small, aquatic creatures with conical shells that are found in both freshwater and saltwater environments. They are usually found clinging to rocks or other hard surfaces, and they feed on algae and other small organisms.