I have four ladies, Golden Comments, who are about a year old. I got them full grown about a month ago, and I noticed three of the four have lost a small patch of feathers around the same place on their necks. Their behavior seems normal, they're alert, active and scratching around and laying eggs normally. I checked for visible signs of lice and did not see any, the skin appears to be normal color. I'm not sure if the more aggressive of the hens was picking on the others - as she is the only chicken not missing any feathers. Any thoughts or advice would be greatly appreciated, I'm a brand new chicken owner. Thanks!