Other forms: limpets
A limpet is a mollusk with a low, conical shell. It's an aquatic snail that attaches itself to rocks in coastal areas.
The single, powerful foot of a limpet works like a suction cup to keep it firmly attached to rocks. Limpets can crawl along the rocks to which they are attached. Over time, a limpet's hard shell grinds a "home scar" into the rock. The limpet ventures from its home scar to graze on algae, and then returns to the same spot. The word limpet is also used figuratively to describe someone that clings tenaciously to another person or to something, such as a cause.