Help!

[Vannahen]

I have 10 month old hens. Large coop large run, 7 hens. I have never seen any aggression, ever. Tho I know it could be happening when I am not around. My favorite girl has all the sudden had feathers missing, is this something she has done?on the back close to tail feathers. Or has others done this to her? What can I do?? I am a first time hen mom. HELP

 

[azygous]

Do your hens free range? Do you have hawks? One explanation of feather loss on the back, when no rooster is present to blame, is an aborted hawk attack - a near miss where the hawk only got away with a few back feathers rather than the chicken.

Another cause can be parasites. Have you looked for crawly things on the bare area and around the vent? Check your perches at night with a damp paper towel to see if you come away with a smear of read indicating mites that have been feeding on the blood of your chickens.

The third and most common reason for feather loss is feather picking. You need to spy on your chickens some afternoon to catch them in the act. If you identify the perpetrator, you can use pinless peepers to hobble her vision enough so she may stop the behavior.

 

[Vannahen]

Do your hens free range? Do you have hawks? One explanation of feather loss on the back, when no rooster is present to blame, is an aborted hawk attack - a near miss where the hawk only got away with a few back feathers rather than the chicken.

Another cause can be parasites. Have you looked for crawly things on the bare area and around the vent? Check your perches at night with a damp paper towel to see if you come away with a smear of read indicating mites that have been feeding on the blood of your chickens.

The third and most common reason for feather loss is feather picking. You need to spy on your chickens some afternoon to catch them in the act. If you identify the perpetrator, you can use pinless peepers to hobble her vision enough so she may stop the behavior.

No mites. Not that I’ve seen, I am in there very frequently. They do no free range until spring. I will start spying on the girls. I’m a nervous wreck, as they are pets to me

 

[coach723]

Some mites only come out at night to feed on the birds, during the day they hide in the nooks and crannies of the coop. So a good check after dark, take them off the roosts and check tehm over with a flashlight or lantern is needed. This has lots of info and pictures which will hopefully help you check for the little buggers:
https://the-chicken-chick.com/poultry-lice-and-mites-identification/Her back feathers above the bare place look a bit frayed also (maybe just the picture) so I'm leaning towards it being feather picking (which often happens on the roosts) or you have a pullet that is behaving like a cockerel and mounting (it does happen sometimes with a dominant girl, expecially in the absence of a male).