As the animal grows, the edges of the outer shell enlarge. The base or bottom of the chiton is formed entirely of a broad muscular foot. This food provides a vacuum-like suction, allowing the animal to clamp down securely on rocky substrates. The foot also facilitates slow movement by backward waves which push the animal forward. The chiton does not have eyes or tentacles on the head, but is able to sense touch and perceive light from sensory cells within the shell plates.
Chiton are herbivores.
At the head end of the animal is a mouth which has a special feeding tool known as the radula. The radula works like a tongue with many tiny teeth that scrape algae from the rocks. Chiton tend to be nocturnal creatures, venturing out when the light is dim in search of food. Chiton respire through gills located in two lateral grooves between the foot and the shells. The chiton has few enemies, but in Northern California there is a predaceous snail that feeds on chiton.