Common limpets are the small cone-like shells that are often seen firmly clamped to the side of rocks in rockpools. Although they may not look impressive at first glance, once the tide comes in they spring to action, moving around rocks eating algae  by scraping it off using their tongue. Their tongue is the world’s strongest known biological structure – it needs to be to constantly scrape algae off tough rocks! 

Limpets move around over the rocks when the tide is in, but always return to their own favourite spot when the tide goes out, following the mucus trail that they have deposited. This spot becomes worn by the edges of the shell, and eventually an obvious ‘scar’ in the rock is created. This ‘home scar’ helps the limpet to better attach to the rock, stopping it drying out until the next tide comes in.