I found one of my blue legged hermit crabs lodged between a rock an the glass of the tank, or at least I found his shell. I found the crab below lying on the bottom, I moved his shell there and went back to check a little later and found that a crab was moving around in the shell. All of my other crabs were on the other side of the tank, so I don't think one stole it. I touched the body of the crab and it was really soft. Did he just molt or what? Or his he dead?