My girls are six months old and have been laying for about a month. I have three nest boxes for six birds but someone keeps laying out in their yard upon a wall in the dirt. They have scratched out a nice little nest there, but I want the eggs in the coop! They don't seem crowded and actually have two coops to go in. The place where she is laying is a good 25 feet away from the coop. How can I discourage this? The coops are elevated, clean and offer privacy.