These crabs live on the sand, mud, or rocks near tidepools, splitting their time between land and sea. They eat algae and animals—dead or alive. Striped shore crabs make the tiny clicking sounds that are heard near tidepools. As they outgrow their shells, they cast them off. The new underlying soft shells harden quickly. Striped shore crabs are common on the Channel Islands. They are striped in black and green, with red or purple claws, and grow to two inches in diameter.