A lot of my chickens have their tail feathers pulled out. My chicken yard is 30 x 42 split in to two runs of equal size. In one half there are 12 layers and a rooster on the other half are 20 17-week old pullets. I know that the rooster will cause feather loss on the hens back and tail but also some of the pullets are missing many feathers and some are missing none. Why are my pullets missing so many feathers? I see the other pullets come up on each other and give them a peck on their tail probably pulling their feathers out. How do you avoid this behavior? They have plenty of running room to get away and I free feed them. What should I do to get my hens to have pretty tails?