Supplies:
A tupperware container (no lid) that's large enough for your largest crab to walk around in and have ample room.
Scissors or a knife, whichever works best for you
Moss, EE, or playsand
Pen, pencil, magic marker, or permanent marker
Tape
Fishnet, vines, or anything small that a crab can climb.
1.)First, flip over the tupperware container so the opening is face down.
2.)Draw a large circle with a pencil, pen, or marker (large enough for your largest crab to fit through) on the top of your flipped-over tupperware container.
3.) Using a knife or scissors, cut out the circle so you have a nice, large hole.
4.) Since the edges are sharp, put tape around them so they aren't as soft.
5.) Dig out a space in your crabitat that's large enough for your container.
6.) Put the container in the open spot.
7.) Put the substrate you had dug out around the container so that only the hole is visible.
8.) Put moss, EE, or sand in the bottom to cover up the glass.
9.) Put something (fishnet is what I used) that can stretch from the bottom of your basement to the main floor and anchor it there with rocks or something heavy and hermie-safe.
10.) Let your crabs enjoy their new basement!
I'll post pics of mine when I get the chance.
Still, I might have to try it. Thanks! 
I woke up this morning and saw my little PP, Stumpy, just sitting in the basement, enjoying the moss! 
