Yes, from my experience. HOWEVER, if it gets wet it is not effective until it dries. I am in Arizona so keeping it dry is not a problem. My girls have never had mites, lice or any type of little bug and I have never had any problem with smells or odors. I sprinkle it all over the run and coop and in the areas they like to dust bathe. I fling it all over inside the coop. Great stuff!! Just be sure to wear gloves and a mask over your mouth and nose, it is extremely drying.
Be sure to buy food grade from the feed store-NOT the kind at Home Depot for swimming pools. Home Depot also carries it with the pest contol sprays but it is expense to the 50# bag you can get at the feed store.