My roo has been a sweet young roo until recently. He's only a little over a year old and is gentle as can be, although he doesn't like to be touched, which is fine. Lately though, he's been pecking some of the hens on the back of the head or on their backs. He's actually chased two of them down to do it. This isn't the kind of chasing that ends in mating, this ends in him pecking them and them running away from him. I'm getting a little worried about it because now I'm starting to see some of the other hens do it to hens too where no one used to do it. Why are they suddenly pecking each other? Food hasn't changed, there are less chickens in the run, plenty of water and room. The only thing that's changed is that we introduced pine shavings as laying material in the laying boxes (which they all seem to hate and I'm clearing out tomorrow).