I am so glad that you asked this... I found some nap-mats at Canadian Tire and I wanted to get them. But I didn't know how to go about this. I guess the same way that I got the little guy that climbed out of the playpen to stop doing that. I stood outside the door and put him back in every time he tried. Now when I put him down he says "no cwiming (climbing)... is sweeping (sleeping) time."