Limpets look like a cross between a pyramid and Super Mario's vicious mushrooms. They are often overlooked when attached to a stone and they move incredibly slowly. Limpets scrape vegetation off of the stones with their grating tongue. Should it feel threatened, it clamps itself to the rock. It closes the shell off practically air-tight, so that crabs and curious people can't get to them. You find limpets on floating objects from other coasts, such as on the base of sea thong.