I have 5 hens a barred rock, white leghorn, Rhode Island Red, Golden Campine, and a White Sultan. I noticed that below the vent of my white sultan all her feathers were gone and there was a wound about the size of a penny. So I isolated her she is always picked on a little because she is so different then the others but this seemed extreme so I separated her until she heals. And all my other chickens were fine. But today I went out and my golden Campine and my barred rock were both hurt with many feathers missing. My golden Campine is really bad above the tail is all ripped up and bloody. I observed them and realized my Rhode Island Red is picking feathers and my white leghorn is then pecking where the feathers are gone creating wounds. How can I stop this. It makes me so stressed when they are doing this.