Hermit crabs will die if they don’t change their shells.

Hermit crabs need shells to protect themselves, and will face survival difficulties without a shell. Hermit crabs have a soft belly and are not protected by a shell, making them vulnerable to predators. In addition, the shell provides moisture and security to the hermit crab. When a hermit crab's body outgrows its original shell, it will actively look for a new shell to replace it. If a hermit crab does not find a suitable new shell for a long time, it will be in a fragile state and susceptible to injury or even death.