Just thought I would post my $0.02 on the subject. We bought our 4 story bubble cage for $50 when they were being discontinuted from Petco. (There had been a problem with a too large of an opening at the top of the cage and ferrets could get out/caught in the hole. We found this out later but our ferrets have always been to big to get through the hole, so no problems there). We bought the cage about a month or two even before we had ferrets since we were trying to save up the money. Instead, we put a stuffed ferret (Rocket the ferret) inside of it and made a game out of moving the poor thing around the cage every day (yes, we were pathetic). Once we finally got our 2 ferrets, they would have nothing to do with the tubes at first. They didn't even like the ramps! They would only use the first ramp to get up to their food and back down to the litter pan. We started making them use the ramps by putting them in their hammock (attached to the top of the cage) so if they wanted down, they had to manuever through something. Took them a while to realize the hole on the opposite top level shelf meant "oops i'm gonna fall to the bottom" Once they understood that, they started using the ramp .. until it broke. (My boyfriend had broke one tab at the beginning, the ferrets broke the other one). To fix the problem, I moved the shelf that was under their hammock to make a stairway up to the top shelf. As for using the tubes that run around the outside of the cage, it took them a good month to start to use them. Our bigger ferret would only climb up in there if we would tease him with raisins and then would look lost once he got up in there. Then one day, I had put them in the cage before they were done playing so I could clean. Next thing I know, I hear this awful racket and I think they are doing something to each other. Look at the cage and they are both merrily climbing through the tubes. Nowadays, the outside tubes are used to dry off in ("mom, how *could* you give us a bath!") and as our little ones personal attack zone ("i am the king of the bubble tubes! no one may enter without a bite on the nose.") The inside tube is used as an escape hatch. ("i'm on the top shelf and mom is opening the door. wheeeee, here i come to try to get out") Oh, and I know all about them not being able to get into the cage while up on those rolling casters. I had one almost hang himself on his collar trying to get into it while I was cleaning parts of it. For a long time, we would put a cardboard box in front of it so they could jump onto the box and then into the cage. Only problem with that was it was a computer paper box and they just loved to open up the top and play inside. Once the top was open, it had to be closed before they could get back inside of the cage. Now they have a ramp leading up to the cage. It's a 12 step bird ladder which we covered in carpet and stapled/zipped stripped tight. It hooks to the middle of the cage door and they can easily run up and down it. It also gives them a new play toy to scratch at. Rowan [Posted in FML issue 2941]