Hermit crabs can suffocate and die without sufficient humidity. If there's not enough substrate, they can die during the molting process. Toxins, such as tap water and paint, are deadly. Paired hermit crabs may fight to the death over territory or a superior shell.

What happens when a hermit crab dies?

A dead crab will become rigid and loose in its shell. If you shake the shell, the crab will fall out. If you suspect your hermit crab is dead, give the shell a shake to see if the crab falls out.

How do you stop a hermit crab from dying?

When you bring home a new hermit crab, place it in an isolation tank with the same humidity as the store. Use a tiny amount of moss if needed to create the proper humidity. The temperature should be at 72F and remain there. Place a very small amount of sand in the tank, not enough for the crabs to burrow in.