Crab unburied his friend, possibly.

[Jaydick484]

I am not totally sure just what my crab Creamsy discovered under the substrate, but he has been acting very strange since. He has never molted, nor even buried at all. I brought him home originally with a friend, Rosie and she buried right away. I brought him another friend, Didgeridoo....they played, looked like they mated, then she buried herself for a few days. It was in the other corner of the tank, away from the other buried crab. She surfaced and buried herself on the same corner as Rosie this time and hasn't come up for a week. I have not heard scratching this time. After a week of being alone, Creamsy started to dig.....in the same corner as the other two. He got shell deep, and then he backed out frantically wiggling his antenna absolutely everywhere. He looked horrified. He actually ran to his food dish and buried his face behind it for a minute, then came up to me behind the glass waving around his antenna. He's never done that before. He's usually very very shy. I felt terrible. If he discovered his friend or mate molting or dead, would he have eaten them or would he be protective still? I came back later, and he had buried that hole back up. Now he's very active. He didn't sleep all day just ate a ton of applesauce, and took a bunch of baths. I can't tell about the smell, because I've been serving him frozen krill, so it always smells fishy in the room. I think I'll be getting another tank, maybe tomorrow, that's bigger. I can't believe they all went for the same corner. I hope they are all ok.

[curlysister]

Crabs often move around underground, so they are seldom in the same location as when they initially went under. The reason we have deep enough substrate and don't overcrowd tanks, is to avoid a crab digging up or coming across another crab underground. If they come across a crab who is in the process of molting and is vulnerable, they will eat them.
How many crabs of what size do you have in what size tank, and how deep is your sub?
Resist the urge to dig anyone up, just let them do their thing underground.

[Jaydick484]

I have 3 smallish/med in a 10 gal. Two are down and only one is up. I just acquired a 20 gal today, but can only move the one into it once I get yet more heating pads and all the new substrate. It will be a process, but he needs room away from the others....and maybe another friend again in the new tank.