For a long time now i've wanted to make a playpen to better free range my hamsters and mice, but I was never really sure how to do it.
*insert lengthy "ideas I had" paragraph here*
Long story short, a girl on the rattie forum made a playpen out of coroplast, shared the idea with the rest of us, and we all followed suit :P
This is the completed playpen. I bought 10 sheets of coloplast, and this pen only uses six, so I can always make it bigger if I feel the need!
This picture shows the pen set up for Pip.