Personally I would spray the inside of your coop
thoroughly every crack and crevice, everywhere. I spray the walls, floor and ceiling on and under the roost bars, again everywhere. I use the dust in the nest boxes. It takes 3 or 4 weekly treatments because it does not kill the mites eggs so repeat treatments are necessary, You may want to invest in the permethrin concentrate. I use a gallon sprayer with a wand which makes it easier to get to the hard to reach areas in my coops. I have used other strengths of permethrin but right now I have permethrin 10. I mix 6.4 oz to a gallon of water. Good luck...
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