Help! Hens losing feathers - not molting.

[lmboland]

I have 6 hens who are all losing feathers on the front of their necks. One has lost all the feathers around her neck. This has gotten progressively worse for about 6 months. All hens are between 3-4 years old. All are free ranging, eat organic lay pellets and table scraps, and meal worms.
All hens are laying, (so not molting), appear happy and are active. They do shake their heads often, but do not seem to have mites or lice that we can see.
We’ve changed the pine-shavings in the coop weekly for the last two months and treated the coop and run with DE, Neem oil, and Elector PSP. The girls have also been dusted with Permethrin, and DE. Doing a tape test at night shows no red mites. Suggestions? Our local avian vet has run out of ideas.

 

[Kiki]

What does their feeder look like?
Is there anything that they could be putting their head through...to get something on the other side?

 

[Kiki]

Also...how often and how much table scraps and meal worms are you feeding out to how many birds?

 

[lmboland]

What does their feeder look like?
Is there anything that they could be putting their head through...to get something on the other side?

What does their feeder look like?
Is there anything that they could be putting their head through...to get something on the other side?

Standard hanging feeder

 

[lmboland]

Also...how often and how much table scraps and meal worms are you feeding out to how many birds?

About 1/4 cup of meal worms a day - just to lure them back to the coop in the evening or whenever we need to get them back in.

 

[Kiki]

Standard hanging feeder

Look around at the fencing...see if you can spot anywhere that they might be putting their head through.
Something that would rub on that part of their body.

 

[lmboland]

About 1/4 cup of meal worms a day - just to lure them back to the coop in the evening or whenever we need to get them back in.

Table scraps a couple of times a week.

 

[lmboland]

Look around at the fencing...see if you can spot anywhere that they might be putting their head through.
Something that would rub on that part of their body.

Will do - thanks!

 

[Nofowlplay]

Also...how often and how much table scraps and meal worms are you feeding out to how many birds?

So meal worms can cause feather loss? And why would table scraps?