Variety adds spice to life. When I was in high school, I once had a summer job working on my uncle's farm. One of my chores was to take care of the chickens. I quickly noticed this one chicken walking around all by itself outside the fence of the chicken coop. I asked my uncle about this and he said watch. He picked up the chicken and carried it inside the coop and set it down. It squatted down on the ground while all the other chickens ran up to it and started pecking it in the head. My uncle then picked it up and carried it outside and let it go. He told me that if he left it in the coop the other chickens would kill it. I've thought much on this over the years, and the only conclusion I could come to, was that the other chickens felt threatened by that one chicken because it was somehow different than they were.