I had a problem that I am hoping if I tell about someone else will not lose a chick. My run is constructed with dog kennel panels. I put chicken wire around the outside perimeter 18" up and 18" out. I then put lattice fence around the perimeter 18" high. My chicks are 5 weeks old. I let them out in the run and somehow one of them got their head caught in the wire, probably chasing a bug. We found her dead and since nothing could get in the run, I can only deduce that she killed herself in the wire. I hope that this will help someone not lose a precious chick. Thanks.