HCA: Hermit Crab Association

My crab is burying shells.
Yesterday he buried 2 and today 4 were burried. He is just being greedy right?

Oh and my crab Chip and Choco spends most time under the substrate. They are just destressing??

My crabs bury shells all the time when tunneling they fall into holes and get trampled on. Crabs love to dig. I wouldn't worry about it. The other 2 if they are new yes. Some crabs just like to hang out underground. I have a few that I hardly see because they like to hang out underground so much.