I have to laugh aran, I did the same thing - error on the security side of things. My entire run in encased, top, sides and BOTTOM with heavy galvanized 1x2 wire. I truly believe, nothing but a human or bear could penetrate the run or coop. Now I'm worried about snakes.....but I don't think so. Hey, you do what you can and hope for the best! Love your run, although doesn't look like mine, the basic "feel" is the same.
Leave my hens alone!!
Mac