As the hermit crabs grow, they periodically need to upgrade their housing to bigger shells. When a new shell appears on the beach, the cramped crabs will form a orderly queue nearby and change shells all at once, with each crab moving into the next bigges

As the hermit crabs grow, they periodically need to upgrade their housing to bigger shells. When a new shell appears on the beach, the cramped crabs will form a orderly queue nearby and change shells all at once, with each crab moving into the next bigges