I recently purchased a new hermit crab from a pet store because I felt sorry for him. He is at least 2 times the size of his shell and his front half hangs out. I purchased some larger shells for him thinking that he hadn't switched because there was not a choice of larger shells in the tank at the store. After getting him home and giving him a few days to adjust to his new surroundings, I took him out to see how friendly he was. He's very friendly, but that's when I noticed that he is missing at least two limbs, and has a hard time getting around because he has to lay on his side. I was wondering if I should isolate him with a few larger shells in the hopes that he will switch to one more his size, and how long might it take for his limbs to grow back, if ever. Thanks.