To be honest, I was worried about using permethrin spray because of the two community cats (one soon to be adopted) that come around and like to sit near the pen enclosure and right at the front door. But I read more into cat owners' experiences here and elsewhere on how how much exposure would harm them, especially given they don't go into the pen or on the coop. At this rate, I'm buying it to double treat(one on one day, elector on the hens and premise the next to kill nits) alongside elector so the mites get wiped, and the chickens mite free so they can be rehomed.
The humidity here seems to really ruin the strength of food grade DE, unfortunately. The past week and some days has been full of only putting as much food as the hens are likely to eat in a day, seeing mites crawl through the food and DE at sundown, and tossing it all out to scrub down the food container. Same with water containers, dustpan, my boots. I love my hens dearly, but I will not miss being in the trenches of the bug war once they are safe and resettled.