Okay this is kind of a silly question but I have a hermit crab. Yes just one. I will of had him for a year in November. My hermit crab is very inactive. He burrows in his corner and NEVER moves the only time he moves is when I take him out of the tank to play or to change food or water. For his water I have a sponge( i was told to do this instead of a bowl because they could drown) well when I change his water he sits on the sponge for like 30 minutes and then he goes back to his corner. I have never seen him eat and I havent ever seen a change in the amount of food when I change it. Is this normal or do I need to do something like add somthing to my tank? Ps Is it ok to use a fishtank light for my hermie tank?