I am quite certain my chickens have mites, and I know I have a rat problem underneath the coop. I have been patiently waiting for the cats to catch these little beasts...But maybe the time for action is now! I don't want to treat all the birds, and treat the coop for mites, just to have them re-infested from rats/mites living underneath the floor. So far what I've done is dusted the coop and the birds with Sevin. I don't know how well I got it into the cracks and crevices of the coop, however. I wasn't quite sure how to get it in there without being enveloped in a huge cloud of Sevin dust. For the chickens I used a shallow box to make a dust bath of kitty litter, dry dirt, DE and Sevin powder. Now I'm thinking maybe I diluted the Sevin powder too much...But I did thoroughly dust each hen with this mixture, and then did it again a couple days later. I figure I'll do it again after 7 days or so? After dusting, I can definitely smell the Sevin on them. But would it be better to dust the straight powder (Sevin-5)? About the rats which are possibly hosting mites...One idea I had was to set off a bug bomb/fogger UNDER the coop, if I could find one that was just permethrin. Maybe something used for fleas. In addition to killing whatever mite infestation is down there, maybe it will drive the rats out into the open where I can handle them myself (I'm thinking smash with a shovel...) Thanks in advance for any advice you can offer!