Hi all! I have been reading about the cages with tunnels on top and wanted to make a suggestion to you. If the cages you are talking about are the ones I am thinking of, beware, those can come unscrewed and the fur can escape. I am still trying to find a scanner so I can send everyone a picture of the cage my hubby and I built. My cage is 7' tall, 5' wide and each level is almost 21/2' tall. There are ramps that can be removed dividing each level (carpeted) and door to the ramps to separate the levels if one gets ill. The cage is lined professionally with sheet vinyl for easy cleanup and we used smooth galvanized 1x1 wire for all the sides and tops of each level (so I could hang hammocks from). The top level is the "play pen". We staggered carpeted shelves so that they could climb them to get to the tubes that are hanging above. They are the ferret freeway tubes (clear) reinforced by duck tape on the parts where the zip ties pressure the tube. The three absolutely love these! This cage was very expensive to build ($300) because we used cedar framing and expensive wire plus each level can be unbolted to be moved - so it could be three separate cages if needed. The bottom has wheels for ease of cleaning underneath the cage. Every ferret owner (or almost every one) who has seen my cage asks me if my hubby will build them one. He adamantly refuses - lots of hard work. If I could do this myself, I would start a business and donate some to shelters but I am NOT a carpenter or skilled at this. I encourage everyone to try and have a cage custom built for your needs because I just have not found any commercially, mass-produced cages that suit all of the ferret's needs and my needs. If anyone out there has a scanner, and would be kind enough to post pics, I will gladly snail mail you a picture of the cage. Dooks to all~ Danielle [Posted in FML issue 2941]