On Sunday, one of the more active crabs went under ground. He came up once the next day and I haven't seen him since...so for four days. Two of the others have been in the same respective spot in the tank for four days. They move their legs a little, but otherwise don't move. I have checked at different hours of the night/morning and they are still in the same spot.
Is this normal? Do you think the one that went under is molting? If they are destressing, how long does that normally take? Do I need to ISO them?
Thanks so much!
Update...one of the crabs "woke up" about a week later and has been moving around just fine. The one active crab is now dug under, the crab that was buried is still buried (three weeks now) and the one crab that hadn't moved much at all died last night.

Crystal