I have 12 hens. They are 17 months old. When they were about 14 months my two silver laced wyandottes started to have bare backs, at the time I thought this was because of molting. Then as the months went by many other chickens got bare backs and bare bottoms too. My only chickens who look pretty good are my 2 white leghorns and broody chicken who is always in the nesting box. I've came to conclusion that my 2 leghorns are the peckers because on many occasions I've seen them pecking the other chickens. I've tried blue coat but it just isn't working. Should I separate them from the others? Any suggestions would be very appreciated!