Like other crabs they grow by shedding their outer ex-skeleton. This is the most important step toward growth a small crab will make. They need to be kept extra moist and in a medium into which they can burrow themselves. It also may be necessary to isolate the crab for a couple of days because they are very soft, vulnerable and inactive. However, this is an important stage of development for it is in this period that any missing legs, etc., are regenerated by the crabs.
Older crabs molt less frequently but require the same care.
As the crabs grow they will need spare shells to grow into and they also seem to enjoy moving into empty shells to select the home that feels best.