Two months ago we discovered them and I proceeded to take apart the coop and pressure wash all the components. Then made a solution of 60/40 Isopropyl and water (It's what I had handy) and sprayed every crack and gasket. Aside: They're called "Blood Mites" (Blutmilben) in German. Kinda Metal. I had no illusions that they wouldn't come back and indeed they did. I wonder if there's anything that can realistically be done about those buggers and if it's even worth doing so. Want to avoid chemicals as much as possible. Any helpful hints from other chiggin wranglers?