Missing feathers

[Chickendad16]

I have been noticing that my chickens are missing alot of feathers and are very red by their vent, on their backs and on their necks. I am not able to catch them by hand to get a better look because they are extremely skittish. Attached are a few pictures that I could get, they are not the best since I can not catch them. What is causing this? We live in PA.

 

[Cassandra Lana]

Do you have a rooster or drake?

 

[Chickendad16]

No, all hens. Could it be mites or lice? I've cleaned the coop multiple times, sprinkled diatomaceous earth all over the floor and even sprayed down the wall will water,oil and dish soap mixture.

 

[Cassandra Lana]

I don’t know much on mites. I would pull one down from the roost with a flashlight to check for mites