HCA: Hermit Crab Association

So i've had this fairly big girl for a month. Last week, I added a whole lot of sand and ee to give her some digging depth (about 6 inches deep). four days later, she digs down to the bottom of the tat. Since this tat is on a glass desk, I can look through and see a leg or two against the tat glass from the bottom, and she scratches once in awhile. I slipped a piece of cardboard between the desk and the tat so light wouldn't get through in case she was trying to molt in darkness. Good idea? I figured if she wanted to molt in darkness she would just dig up a bit and have sand cover the opening.

Would it hurt to try and pull the cardboard back in a week or two?

It should be fine to take the cardboard out for a peek, but not to often. Don't wanna freak the crab out. Good luck if this is a molt!

lol, so now i've got 3 of my crabbies that dug to the glass. 2 went to the bottom, 1 went down a couple inches, then dug horizontally to the front of the tat.

I peeked earlier today just to check up on their status, I couldn't see the big girl as much now...she got some sand and covered the opening. BUT I noticed my small one that went down a week ago...she's at the bottom of the tat, clearly visible, thankfully moving. The other digger is a big girl slowly digging more downwards from the glass. I pretty much have an empty tat right now...except for 1 that's sitting in a dark corner under a hut. sigh...