HCA: Hermit Crab Association

I have 4 (purples I think) crabs in a 10g tank (the largest I can maintain atm). I just received these guys yesterday, so I had set up the tank with 1inch of play sand as a temporary substrate until I could buy some eco earth. Bought the earth, and came back to find 2 of the smaller guys buried (which is fine right?). Knew I shouldn't go around digging to find them, but accidentally opened the tunnel of one near the water dish. Left him exactly where he was (he was alive but didn't really react) and gently covered him back over with eco earth. His hole is right up against the glass, and I've seen no movement, and I'm pretty sure his hole didn't collapse, but I'm not certain. Was he molting, and if so, did I just screw him up? New to the crab arena, thanks for your help.

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Update: he is now digging in his little spot. Is this normal molting behavior, or is he trying to get out? I can't tell, but he seems to be digging sideways, away from the glass.

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Hi! Digging is normal behavior. When my crabs dig down and are exposed next to the glass, they'll usually "cover" that spot because they like their privacy. Don't push down to collapse or compact the substrate. Also never try to re-bury a crab. Crabs don't molt immediately, they dig down for awhile see if it's safe and then molt, so I wouldn't worry. You can gently place new substrate on top of old, the general guide is 1" per 24 hours.