My chickens have been suffering with northern fowl mites since February. I have tried a couple of different things, but they never seem to go away! They are driving me absolutely crazy. What I've been able to do is basically control the infestation, but I can't get rid of it. I've tried giving each hen a bath with a flea shampoo containing permethrin, I've added DE to the coop and their dust bath and I've also tried giving them all an oral dose of ivermectin. I have heard that Elector PSP is the best; however, I can't seem to find it in Canada, and amazon.com won't ship it across the border. Anyone know how I can get some? The plan is to give the coop a good Spring cleaning this weekend and I'm hoping I'll be able to give them all another treatment. Any help is appreciated!