Thanks for all the dusting info. Our hen suspected of having mites has a small balding spot on her neck. I've dusted that area and also the vent. Vent area looks pretty normal except for a couple black dots (can't tell if it's poo dust or mites) and what looks like new feathers coming out. How do you tell if it's a new feather or a feather that's been chewed on? We're totally new at this, so any help is appreciated. Thanks again!