Chicken losing feathers

[niagarachickens]

My 1 hen of my flock of 25 has been losing feathers around her head for the last 3 MONTHS. I do not think molting is the issue as it should have finished by now. And I have checked her many times for any visible lice or mites. I am also leaning away from any lice or mites as my other 24 do not have any issues similar to this. The hen with said issue is in the top 3 of pecking order and I never see any forms of bullying or picking on her. She has also lost quite a bit of feathers on her chest

https://www.reddit.com/r/BackyardPoultry/comments/1lw1qn3/whats_wrong_with_my_chicken

 

[500Chickens]

My SS has that too, and it's from when she used to get picked on and the feathers never came back. (she hasn't gotten picked on in about a year)

 

[niagarachickens]

My SS has that too, and it's from when she used to get picked on and the feathers never came back. (she hasn't gotten picked on in about a year)

Thanks for the response! I do not think my situation is due to her being picked on. Over the last 3 months it continues to get worse losing more and more feathers with no visible signs of being pecked or any bleeding. And the big bald spot on her chest as well does not seem indicative of being bullied or picked on. I am stumped!