I always thought I could never cull a chicken. Until I caught one of my favorite hens literally eating an egg. To much time work and energy to let her continue. I am not sure how one would "train" them to stop. I knew I had an egg eater for two years. I just didn't know which hen. When I literally caught her with egg on her beak. It was something I had to do. Maybe others might have ideas of how to train a naughty hen. In my opinion as you learn and grow one will do what one has to.