Yes, that's the bugs.. don't wait to treat. Nice catch! I can see her skin is a little red instead of light pink.
My preferred method... a permethrin based spray.
Soaking is not required. Just a small spritz... right below the vent, in each wing pit, and at the back of the head where the base meets the neck... Making sure feathers are parted and spray hits the skin. Under $8 for this bottle and it lasted my 2 large goats, 3 medium dogs, and 82+ birds for more than 2 years. But it comes under other brand names like Gordon's... sold in the cattle section, but labeled for use in chickens and does NOT require any withdrawal time for eggs. I bought it for mosquitoes but discovered its' many uses.
I'm still learning how to identify these things... yours look like (maybe) northern fowl mites. Either way, this stuff works!
The first time I saw nits like that... I thought it was clumps of dried on mud. It is NOT.
Retreat after 10 days (or according to directions) to completely interrupt the life cycle and get anything that still hatches. This will ensure they are taken care of and help avoid them building resistance to the drug.
If you have a hard time catching your birds... wait and do this after dark using a flashlight or head lamp. Treat everyone. They *should* stay in their place on roost if you keep it dark enough. Easy peasy.
I also treat nest boxes and coop floor and roosts.
