I've never seen free ranging chickens stay where they are supposed to. I will only let mine free range an hour before they roost, otherwise they go in my neighbors yard, and have even gone to my other neighbors and opened up bags of sweet feed she had there for her cows. She's so sweet though, she wouldn't even let us replace it, but hubby does a lot of work for her as far as fence maintenance and other things she can't do herself. I'm not sure if the electric fence would hurt your chickens or not. We used to have electric wire ran around the outside of our chicken run, and one of our hens just took her chicks out of the coop and the chicks ran out of the coop and hit the fence. One right after another. I thought they were dead, it knocked them over and they were so tiny. I screamed at hubby to turn the fence over. The moms (2 hens were taking care of the clutch) were nudging them, trying to get them up. They finally got up, looked like they were drunk for a while, but ended up fine.
