My rats have been sleeping in a cardboard box every night for a couple months which has been chewed to death and peed all over. So last night I go to Petco to find a new house. I first planned to get a regular igloo house,but it had no bottom and I didnt want my rats sleeping on the bars. Then I was going to get one of those little stick houses that look like a swallow nest,but I figured they would chew it apart with time. Right when I thought it was hopeless, I wandered across a chinchilla bath house.its clear blue so they feel enclosed but I can see what there doing in there, it has an elevated hole to get in which forces my little fatties to get some exercise hopping, and it attaches securely to the bars. The best part is, it came with bath dust,which I gave back to the lady working the register to use on the chinchillas at the store, and I got a 10% discount . My rats love hiding in here and i definetly recommend it as a house. Heres a pic.