Old log coop, dirt floor, straw attic… mite/lice control?

[khind]

The very first thing I would do is remove all the straw from the attic and remove the ceiling planks. Can you please post pictures of your entire coop? If there are ceiling joists, you may need to attach chicken wire to the bottom side to prevent chickens roosting up there.
You shouldn't need the straw for insulation and the straw is doing you no favors.
How cold do your winters get?

This is going to do absolutely nothing to cure your problem.

I would buy 10% concentrated Permethrin. Mix it up per the label instructions for the coop in a 2-gallon garden sprayer and in a trigger bottle for the birds.
Strip every bit of bedding and straw out of the coop. I mask up and use a leaf blower to blow out excess dust with all the windows and doors open.
Use the garden sprayer and spray from the ceiling down. You don't have to saturate everything, just dampen it. Make sure you pay attention to the crevices where mites hide. Put a fan in the coop to accelerate drying and put down fresh bedding. Maybe half what you'd normally use because it's all coming out in 7 to 10 days for the next treatment.
That night treat the birds. Using the trigger spray bottle, spray each bird under both wings, under the hackle feathers at the base of the neck, under the vent in the fluff and on the chest lifting feathers to get to the skin.
Repeat the above in 7 to 10 days.
With very bad infestations, you may need a third treatment.
Permethrin is not dangerous to cats once it is dry. No animal should be in the coop when it is being treated and won't be let back in until it is dry.

This is not a good idea with old wood.

I'm unfamiliar with this product.

This is a very good product but if you are complaining about the price of Permethrin, this is about 15x more expensive. I have it. I've used it. I love it.
You would do the same treatment as above except when you're done, you're done. No second or third treatment.

Again, don't bother. It isn't going to treat the insects.

I would use this (or hemp bedding after you are completely rid of the infestation).

Quick question: Do you think it's
absolutely necessary to wait til roosting time to dust the birds if they're kept out of the chicken house til it dries? I'll be treating mine today, and I feel like it might be easier for me to take the birds out of the run one by one, treat and leave outside in their enclosed large yard, and then treat their coop and run.

 

[DobieLover]

Quick question: Do you think it's
absolutely necessary to wait til roosting time to dust the birds if they're kept out of the chicken house til it dries? I'll be treating mine today, and I feel like it might be easier for me to take the birds out of the run one by one, treat and leave outside in their enclosed large yard, and then treat their coop and run.

If you want to chase chickens around your run, that's your choice.

I don't like doing that for two reasons. It's a pain in the neck and it stresses the birds. It's much easier for me to just walk in the coop and pick them up off the roost one by one.
There's no struggling.
There's no chasing.
And it's very easy to just work my way around the roost until everybody's been treated.