I am a first time rat owner. Ive had my girls for about a month now. I have a couple of questions that Im hoping someone can answer for me. 1. This is the cage my rats are in They always pee on the third level of the cage and as a result my room always stinks. Even if I wipe that level down multiple times a day it still ends up covered in pee by the end of the night. My rats are constantly walking/sitting in their own urine and I feel so bad, but Its so hard to keep up with. Im looking for suggestions on what I can do to fix this problem. Can rats learn to pee in a litter box? Im thinking of buying some bedding to put down on just that level to hopefully absorb some of the urine and to help with the odor. Any other suggestions? They poop on the bottom level of the cage so it falls onto the litter mat but for some reason they wont do that when they pee. 2. I switched their food to oxbow adult rat food and one of my rats has gained some weight. Im worried the rat is going to continue to gain weight. Right now Im feeding it unlimitedly with the occasional snack, should I limit how much Im giving them each day? If so how much should I give them? 3. Can I use cat litter on the litter tray. Ive read not to use cat litter in rat litter boxes because its too dusty and can become a lung irritant, but Im just wondering if it would be alright because the litter tray sits under the cage and as a result they would never come into direct contact with it. Right now Im using corn cob litter and its not working. Can I use a walnut based cat litter? 4. Do I need to give my rats hay? I believe it says to provide hay on the back of the oxbow food bag but I cant find much online about it.