I have the large white wired play pen, with the blue floor mat and also blue top mat. Seems like Diesel, the Houdini of my ferrets, manages to get out of it from the top. I have about 35 clothes pins helping hold down the top canvas type material, but he still is able to vault himself up and hold on to top long enough to push out the clothespins, then over he goes. Any one else run into this problem? I need advice on how to keep the top mat down sturdy enough that he cannot push thru the top, or else some other way that he cannot manage to pull himself up to get there....help! Leah in NJ [Posted in FML 6843]