Limpets are incredible organisms. They can withstand the heaviest seas, can live despite being baked by the sun and desiccated on hard rock, and may reach 20 years old. They live a life roaming underwater, feeding on algae growing on the rocks and, at just the right time, return home to the exact spot they left.
As they settle down into their comfortable home position, they wear away the rock. Eventually they leave a scar on the rock where their shell fits a slight depression in the rock perfectly. It’s not much, but a home scar is what a limpet calls home.