In Biscuit's cage, I have a "Fun-nel" or whatever it's called....a big fat tunnel thing that's got a bit of a curve to it. At night, he likes to push it around and play with it. Well, this morning when I woke up, he had somehow managed to get it to stand up on one of its ends. It's not propping up on anything. It is so weird the way he did that, I'd love to have a video seeing how he managed to do that.