Chickens can DIG!!! There are many places where I've had to stick pavers or bricks around where they dig so they don't undermine concrete blocks or dig right out from under the run walls. There's a concrete block sitting tall, that held up one end of a roost that was darn near about to fall, I fixed it before the pics so it's not included here. It's pretty crazy, so thought I'd share some pics of what parts of my run look like where I need to add some more deterrents. If you have any structural blocks, posts, etc...protect them from The Chicken Excavators!!! Here I added a couple pieces of concrete, they just dug out between them...this hole is about 4" deep. This is just in the middle of the run about 6" deep, I'll leave it as is, the line of pavers covers a drain pipe...so they won't dig it up. Old gate and grazing frame leaning up against run wall. They have dug down all around them to they are just held up but some dirt.