My 3 year old hen is loosing feathers around the neck and Vent. I examined her carefully, no sign of mites or lice the skin looks pink and healthy just no feathers. She's eating and drinking. She does shake her head a lot as if trying to shake something off. Around her neck there are lot's of nubby looking, short "beginning of new feathers"? Any ideas, suggestions would be greatly appreciated. Tarja p.s. We also recently had a hen with maggots, she's all better now, her butt is healing nicely. This does not look like maggot problem.