What is up with my chickens feathers?

[Nirrem29]

The feathers on some of my chickens backs are fluffy. Have been like that for a month or so. I thought it was mites after doing some research but it doesn’t seem to be getting better with treatment. Anyone know what is going on!?

 

[DobieLover]

Do you have a rooster?

 

[Nirrem29]

Do you have a rooster?

No rooster

 

[DobieLover]

What exactly are you feeding them? How large is their coop and run and how many hens do you have? When did you start noticing it?

 

[Nirrem29]

Extra layer pellets from Blue Seal. 9 hens. Plenty of room for them, We built it all with room for 15 or so. I forget exact dimensions right now but can check in the morning if you think that info will help. Started about a month ago.