the crab incident

Isabel came running downstairs to tell us that Ansel had ripped one of the hermit crabs (our beloved pets) out of his shell. Ansel has been more interested in our crabs lately. Every morning as soon as I get him out of his crib he walks straight into the play room and gets the crabs out. Anyway, we ran upstairs thinking if you pull them out, they will die....they'll hold on so tight that they just rip in half. Also, I don't understand how Ansel could try pulling the crab out without getting pinched real bad and dropping the crab. After arriving in the play room we saw there was a naked crab (shell...less) on the carpet with all the shells in the tank. It was VERY weird. We didn't know what to do at first, but we just put all the empty shells next to the crab and he got in one of them and we put him back in the tank. BUT, we have NO idea how the naked crab got out. We are guessing that he must have just gotten out of the shell himself and Ansel put the empty shell back into the tank. But, I have no idea why our crab would just get out of his shell with no other shell in sight and outside of the habitat. Anyway, it was pretty crazy...but the crabs seem to be doing just fine.