Is this mites or molting? And how to I get rid of mites?

[FeatherSwift93]

 

[Wyorp Rock]

Feather loss along the back like that is usually due to being mounted. Sides of head could be feather picking. What do you feed, including treats?

Look them over for crawling bugs, check your coop at night with a light and run a paper towel along the roosting bars to see if you get bugs (mites).

Lice generally live on the bird, mites mainly live in housing and come out to feed at night.
Use a Permethrin based poultry dust to dust the birds and use a spray to treat housing. Do this in 5-7day intervals.

 

[GodLovesU]

I would look through their feathers to see if you can see any mites. Here’s a couple articles on mites and moulting:
https://www.backyardchickens.com/ar...-or-mites-on-chickens-using-permethrin.79711/

https://www.backyardchickens.com/articles/what-happens-when-chickens-molt.67366/