There is an isolated population with a wide range disjunction at Bamfield on Vancouver Island, Canada.

[3][4] They enjoy hiding in small crevices within rock, but will emerge at night when there is less danger of predation.

[4] This opportunistic predator's diet consists of green algae, red algae, brown seaweed, diatoms, worms, mussels, small decaying organisms, limpets, snails, flies, hermit crabs, seaweed, isopods, and sometimes even each other when the lesser crab has just finished molting.

[4][6] Generally they are eaten by seagulls, octopuses, rats, raccoons, and humans, but are vulnerable to other organisms especially during their juvenile stages.

On rocky shores they will hunt more often than they forage, and under the cover of night, whilst in intertidal pools they will focus more on herbivory even during daytime hours.