Ok, this is our first group of chickens and I need help. We have 2 Australorps, 2 Easter Eggers and 1 Rhode Island red. We noticed one of the Australorps toosh was bare. I have been trying to research why. We have checked for signs of bugs, can't see anything. So then we thought maybe boredom since it's winter. Today I noticed our one Easter egger, Scarlett, is pecking at all the girls' butts and eating the feathers. We give them organic layer feed, plus oyster shells. We give them black oil sunflower seeds. We occasionally give them raisins. We also hang cabbage for them to play with and eat. 4 out of the 5 have been laying eggs for around a month, month and a half. Scarlett is starting to show signs, but hasn't started laying yet. They are all almost 7 months old. What are we doing wrong and how can we stop this behavior before it escalates into something worse?