As I was re-using garden rocks/edging and my chook pen was about 6m x 3m squared, I chose to concrete in my rocks under my colourbond fenceline which was the boundary on two sides of my chook pen. I wanted to be sure that no dog would be able to dig beneath this fence to reach my 3 girls. BUT, if I had a chook pen with wire all around, this dog/fox proof fencing to prevent entry via digging is perfect. And perfectly easy to construct 