Has anyone made a successful rat play pen? One they can't escape from? Here are my thoughts and reasons: my two girls live at the school in the library, I'm the librarian. I have a very small desk area tucked in a corner of the library. The floor space is about 6 feet by 6 feet. For about an hour a day, I am stranded at that desk. I'd like a play pen around the area including me and my chair. I was thinking it would be a great time for them to have some free range time but I'd have to have a way to enclose them and keep them from getting out. I know I can't build a wire enclosure because they are too good at climbing! Has anyone done something similar? What or how did you build it?