I've seen a lot lately on putting a wire skirt around the pen but they don't mention it should extend 18"+ on the ground and on the OUTSIDE of the pen and not on the inside. My neighbor put it on the inside and it did NO good. Foxes are smart, but they don't think about digging 18" away from the pen frame. If you really want to do it right, put is underground a couple of inches and put dirt or gravel over it. 1" hardware cloth is great for the whole pen and also to use for the skirt. Reason for the hard wire cloth is it keeps birds out that carry mites and germs and also if a hen is sleeping close to the chicken wire pen, a raccoon can easily reach in to get her, can't pull her out, but can sure hurt her especially on the neck and head. It also keeps larger snakes out. Raccoons can even undo most hooks so be sure to use a latch they cannot work loose.