Chitons cling to the rocks with their foot at low tides. When the tide is high and it is safe, they venture out to eat by scraping algae, bacteria, and diatoms off the rocks. Chitons blend in well with the rocks in the intertidal zone. Their shells are made of eight overlapping plates. Like pill bugs on land, these armored animals roll up to protect themselves from predators. The three-inch-long mossy chitons are one of several species here. Their mossy looks come from the stiff hairs that fringe their edges and the algae that often grow on their shells.