So in the two bottom cupboards are litter boxes. I wanted to have the two sides symmetrical so that if I need to separate the two of them for any reason I can. I also wanted to do something like this litter/hay box combo that you can get on Etsy It took a bit of doing to figure out how to make it fit in a cupboard but I did a box for the hay and then a platform box for the other side of the litter, for them to be able to get on the ramp to the next shelf. Unfortunately the first night they got here, I didn't want to leave them in the tiny cage I'd brought overnight but neither did I have enough hay with me to completely fill the hay box. The holes in the box are more than large enough for Lahi to fit through, and overnight he decided the hay box was a wonderful place to hide in. I bought a new bag of hay the very next morning and Lahi has been furiously digging it out of the hay box ever since, wanting his hiding place back xD oops As I mentioned before, the shelves are covered in clear vinyl to protect the wood (which has already come in handy, one of them must have hung their little butt over the corner of the litter box and managed to pee outside it), then a layer of EVA foam, covered in polar fleece. What I ended up doing is making almost pillowcases for the foam. I got a roll of sew-on loop Velcro and a roll of stick-on hook Velcro and so now the fleece case is completely removeable and machine-washable. However I am noticing that while the fleece may be soft, soft doesn't equal traction, and I am noticing their feet slipping a bit as they walk across it. :/ the cotton mat I put in the centre later gave them more traction but it's not really soft and giving under their feet! ARGH I can't win! They do like the massive mirror I mounted on the wall of the centre cupboard. For the room itself when they run around, I have a woven cotton rug I brought with me from the previous place after washing it thoroughly. I then also bought a woven jute rug to cover the rest of the floor. It's got lots of traction and is very safe if they were to chew on it, but I didn't foresee how uncomfortable it would be. The woven texture is hard and just uncomfortable for me to stand on, kneeling on it is completely out. They haven't shown a preference yet but I'm thinking it's going to get covered with another cotton rug.