why did it die

Question
i had a hermit crab that began to move less and less and eventually stopped
moving for days, a few days later i noticed it was lifeless, and assumed it was
dead, once i could smell that it really was dead i gently pulled its body out of
the shell and to my suprise its dead body had come out of the exoskeleton,
through the rear of its body.  Why did it die? was it trying to molt while still in
its shell?

Answer
Ryan, what happened to your crab is unfortunately quite common in hermit crabs. They do molt in their shells, that wasn't the issue, they need to be in the shell for protection while their body is soft. But often hermit crabs DO die during molting. They sometimes get stuck and can't get the exoskeleton off and they either die from exhaustion of tryinhg to free themselves, they die from sheer stress of being stuck and vulnurable, or sometimes just die from dehydration.  It's a very risky time for crabs when they molt and it's quite common to lose crabs during that time, even for people who've owned them for YEARS... It's just a difficult time for a crab and getting stuck in the shell makes it vastly worse. Just about the only thing you could have possibly done to help him would have been right there at the moment he got stuck with a pair of tiny pliers and broke the shell off for him, but if your crab was small, you would have ended up crushing his soft body... There's not much you can do for them when they get stuck like that. There are some things you could try in the future to PREVENT it, such as raising the humidity and providing lots and lots of salt and fresh water when he is going into molting mode (slowing down, hiding, eating a lot, etc.) and just watching him closely. I have been very fortunate that all 3 of my crabs are very good molters and I haven't had much trouble out of them. You could also try using coconut bedding (forest bedding, bed-a-beast, eco-earth) in half of your tank and if you notice your crab starting to go into molting mode, block off the sand area, apparently coconut bedding works wonders for molting crabs, and a lot of people swear by it with regards to making molting easier. Don't give up, what happened to your crab is a saddeningly common thing and it was in no way your fault, and you should try again with new crabs if you feel up to it, they are awesome little critters to own.