if you hang something from the cabbage family for them, they should have fun laying with it, plus it's good for them. Just make sure they have grit and they have to jump a bit to get to it. Maybe put it lower at first so they learn to like it, then raise it up. That is a suggestion in all three of my chicken books, but for the record, I have not tried it myself. I have read many posts on here, though, and people seem to like this trick.