i had two hens that just plucked feathers out of all my other chickens, is this a common issue. I put them in a pen alone,so they started plucking each others tail feathers. I just sent them to my own freezer camp. Please give advice on how to stop if this happens again, I have many chickens this is my first feather pluckers. I have chickens that peck but not pluck then they ate the feathers.