Thanks for the reply, Glenda.
Trust me, when I tell you it's not mites. I've had experience with those and adobe ticks (not here), this is DIFFERENT. The only way I could examine these birds for mites any closer, would be to kill them and pluck them. No mites.
Mice? Not likely either. Like I said in earlier posts, My coops are pretty much rodent proof. Residential building type doors and windows. I've checked these guys' coops at all hours of the night and day. Never seen a mouse in the coop. No mouse droppings in the feeders. Never found any mice nests in the area with feathers in them. I find more evidence that mice have been in my garage, than the coops. And the cat sleeps in the garage. Mice prefer to build their nest with dry grasses and chewed cloth around here.
These chickens have their feathers broken VERY evenly. I'd be hard pressed to do it this carefully, even with hair clippers. Is it possible, that they may have been exposed to something detrimental to their diet, during feather developement, that would cause such even breakage in the feathers? Thanks again. Hope this gives you more information, to come up with more ideas.