If you splash a red mite in the morning, you will see blood

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I eradicated it after treating and using DE in summer within 2 months as far as I could see.
After cleaning and using DE the first time, the red mites kept coming out of their hiding places.
Cleaned everything a second time and took out some slats, the poop board and construction wood. Found hiding spots with red mite eggs.
Next I sprayed the corners and cracks with permethrin bc I needed a quick fix, going on a vacation soon. I couldn’t ask my neighbours too much. Bc I had a broody in the nestbox where the infestation probably started (having chicks in there before) , I did spray this one hen with permethrin. Not the chicks and the other hens. The hens got a little DE in between their feathers on their backs.
Permethrin isn’t allowed in the EU (Europe) to use on chickens who supply food. But they sell small spray flacons for songbirds and parrots.
I also bought special herbal mixtures. A liquid and a powder (finecto+) to add in their feed and water. Its not a poison and harmless in the right dosage. It makes the blood of the chickens unattractive for mites.
Besides this I used DE in their sandbath and in the nestbox, as a paint on the wood, an extra layer on all the cracks. I have a sand floor and used cardboard and sand under the roost for them to clean the poop easily. I replaced the cardboard every week.
After a month I only saw an occasional small mite in the corrugated paper rolls. After 2 months it stopped completely.