You should offer food to your crabs every day. It’s true they only eat a little bit, so adjust how much you offer by how much they eat. If they finish everything you feed them, add a little more, they may be hungry and not getting enough if they finish all their food. You want to see a little bit left over. You don’t have to provide food when they are molting. Hermit crabs will eat their shell during this process. Once it has emerged from the burrow, continue the regular feeding schedule.