Has anyone built their own cages? Right now I have my rats in an aquarium and I really have to change that soon, But I haven't found the right cage for them, I want something that they'll enjoy, not something that they'll just sleep in.... Anyway, if anyone has built their own cages I'd like some advice, whether its a good or bad idea, I know a guy who built his ferret a cage, and it has yet to escape it so i'm thinking about talking to him to...