I separated the roosters from the affected flock but still have 1 roo for every 12 hens. Barred rock cage separated and white leghorn cage are al separate. These hens in photos are just some of them and they are in a separate coop which is like 10' x 12' in size. The main coop where the other hens are is larger than that coop size. I don't see any problems with the barred and white leghorn with roosters tho. But what worries me is these hens. They are mixed breeds, black and red sex links, white leghorn, some are buff orpingtons and rhode island reds. The buff and rhodes are the older hens but they don't have any bald spots.like the others. I wonder if it is due to pecking disorders because I checked for mites and don't see anything but I'll double check again. From the main coop where most of the hens are have lots of bald spots, on their neck, head, back, breasts and butts.
I give them boiled eggs everyday, greens, tomatoes, grass clippings once a week. We have a small farm that we harvest veggies and berries so they enjoy the produce, too.
The roo that died was the worst I've seen since I raised chickens. When I first started noticing he's sick due to scruffy looking feathers and losing some, I thought it was just molting until I noticed his neck looks like it was getting twisted. I separate him immediately and researched. He's gasping for air and drools and what I found out, it might be gapeworm so I gave all the chickens ivermectin dosage according to the product directions for 7 days. But the poor roo didn't make it.

I think I will be trying the permethrin just to make sure that there will be no mites.
Thank you for the advice Aunt Angus! I truly appreciate it
