I started with 7 chicks last March, 2 ended up being roos, which have luckily been rehomed to a farm. Now I have 5 great hens in a HUG yard area for them. Built a second coop for more hens coming over next 2 months which will total 16 hens by April 1 in 2 huge coops/yards. My second coop which is smaller has a 4 inch concrete footer all the way around. But my original one only had 4x4 and sunken timber along with a 6 inch outer layer of chicken wire/mesh. But my Girls (5 of them) are digging the CRAP out of the inner perimeter. Any suggestions on what I can put around the boarder INSIDE the run to block the digging to make sure the don't Shaw Shank the coop? Thx