Have a dear friend struggling with northern fowl mites and losing the battle. She sprays, dips, and shampoos with Adams, dusts with sevin and pymethrin, and uses ivermectin drops. Coops are cleaned frequently and bombed with Adams room fogger. Bedding is stirred and amended weekly with either insecticidal dust, wood ash, or red cedar chips. She has mostly crested breeds, and weekly inspection never fails to reveal a number of birds affected- the crests are like mite nests. I've run out of advice for her, and promised I'd put it out on the forum to see if anyone has ever defeated these pests. She has a large flock and is spending about $100 per month on treatments and way too much time dealing with this, and is talking about throwing in the towel. I just read about filling the end of a stocking with sevin dust and hanging in coop doorways so that the birds are self dusting every time they brush against it. Can anyone help?