could this be feather mites

[cmom]

You should quite spraying her for awhile. The mites can develop a resistance to it. I usually spray 3 to 4 weekly sprayings and then stop and I haven't found anymore pests on my birds. I just recently started spraying in the coops. I done 2 weekly spraying and in 2/3 days will do a third spray. I've been spraying because there were quite a lot of flies around the coops. I have to clean out the poop pits under the coops. I haven't done it lately because we have been getting rain every day. The permethrin treatments have taken care of the flies for now.

 

[aart]

is this feather mites

Feather mites, or de-pluming mites, live in the feather shaft and in the feather follicle and are naked to the human eye....so it's really hard to ID them for sure amd there is not much info out there about them.
I think they have to be treated systemically rather than topically.