"I bought a double unit critter nation for my 5 rattie boys about 2 months ago and they love all the space they have now. I love how easy it is to clean and move (even though the cage is heavy) since it has casters, it glides along easily anywhere in my house. The doors open up the entire front of the cage, making it very easy to reach anywhere inside. My only small complaint is the pans, I wish they were a little bit deeper. I do use fleece and litter boxes with my boys, but they do not always use their little pans ;) and still throw quite a bit of stuff out every night and since they are constantly chewing up the fleece liners I wish I could use bedding. :) But compared to other cages on the market for rats, this is hands down the best choice. I also like that the shelves and bottom are solid, so safer for their little feet. It looks more like furniture than a cage. Ours is kept in the living room and looks very nice."