I recently noticed that one of my hens is losing the feathers on her head and also has broken feathers at the base of her back just in front of her tail feathers. I dont have any roosters and it doens't look like she is being pecked by the others (no blood, no feathers in the coop, etc). I also haven't observed any pecking or aggressive behavior. She is only about a year old and has never been de-wormed; however, I havent seen any posts that indicate that feather loss would be the result of worms. I have doused her a couple times with DE in case its mites or lice (neither of which have been seen by the naked eye). Recently, she has been gaping her mouth as if she is going to squawk or crow but nothing comes out. Not sure if this is a symptom or a result of stress. Any help would be appreciated. She is still laying to the best of my knowledge.