I have a 1 1/2 year old hen who is loosing feathers on her head and now her neck. This has been going on all summer. I don't feel that it is molting. Some of my other hens are molting and it doesn't look the same. Her skin is not broken but in places looks red. She is still bright eyed and active, she eats well but seems to be losing feathers and it seems to be getting worse. I have tried to check her for lice and mites and I have not been able to see anything. Does anyone have any thoughts?