HCA: Hermit Crab Association

I inherited two crabs from a friend two months ago and bought an additional crab from Petco. I know my friend wasn't taking proper care of hers. They were in a small plastic tank with no heater, no salt water and fed only pellets. I studied up and learned how to take better care of them. I have been giving them nutritious and varied foods, access to salt water and put a heater in the tank. A few days ago I finally got them a bigger tank and better substrate. I moved them from a 2 gallon tank with dry sand into a ten gallon tank with moist coconut fiber bedding. I probably put four inches of bedding down. A few hours after putting them in I came back to the room and they were all gone. I know you aren't supposed to disturb crabs while molting so I didn't want to dig too much I moved some surface substrate and glimpsed the shell of the larger crab but no sign of the smaller two. My questions are: What is going on? Are they molting? Would all three decide to molt at the same time? Could they be trapped? I heard a lot of noise coming from under the substrate the first night, a little noise the second night and nothing since. I'm just not sure what is going on and I will be very sad if they die. I was so excited for them to have their new swanky habitat. Any advice would be appreciated.

It is important to leave them alone when they are under the sub. They sometimes dig for whatever crabby reason they dig, seems like fun. They also dig and bury to de-stress, to molt, to get some relaxed alone time. Let them do their thing. If you disturb them, it causes them stress.Is the sub sandcastle consistency? As long as you keep it so and the temperature and humidity are good that is the best you can do for providing optimal conditions. Good food and waters, climbing and hiding ability also important.Once they are all back up, consider adding some playsand (like what you would get from the hardware store as opposed to the dangerous calcium sand from the pet store) to the substrate. Using straight coco fiber has some drawbacks and most people are happier with a mix. Wait though until everyone is back up. Ideally you should have enough depth to be at least twice the height of your largest crab but a minimum of 6 inches even if that is more than twice.Keep up the improvements, your crabs appreciate it.

Thank you so much for your reassuring answer. I will cross my fingers and hope for the best!

Actually, one more question: if one comes up but one stays down should I move the one(s) that come up to an ISO? Are molting crabs in danger while they are buried or after they come up? If they all molt at the same time does that mean they will leave each other alone and not try to eat each other?

There is no need to move anyone unless you have someone who is surface molting. Generally three are able to spread out enough in a 10 gallon to be fine. Watch as they come up for bullying but I have never really had a problem with molters being attacked except when I have done something to disturb the molt.

One more question: if they are down there and alive (molting or just de-stressing) would I hear them making noises? I haven't heard a single noise in days (and I am in there at night). Is this normal or a bad sign?

I never hear mine so I would say try not to worry.