I'm new to raising chickens. I have 27 3 1/2 week old chicks, various breeds. I found one dead this morning, and now I have 5 in separate boxes because of bleeding and they are pulling their own tail feathers out and of course once the others see it, they start pecking too. I don't know what to do to stop it? I have called every where asking for a spray or something, it seems to be the light colored ones, the BO and NH reds. So far the BR and Wellies and Golden Wyandottes seem ok. Any help would be greatly appreciated, I don't want to lose all my girls! Thank you!