So, if I am reading this correctly it would be Okay to use the Permethrin as a preventative? Tonight I rinsed the back end of my Sussex as she seems to be getting a lot of poo stuck there lately. *sleeps in nesting box - habit from previous owner* She was not thrilled with this treatment but was able to clean a bit off. The area looked a little irritated. Looked quickly did not really see any critters moving around, but wondering if maybe I missed them. I think I want to use the powder in the nesting box again as a preventative, just sprinkle on top of the pine shavings? My younger birds are not thrilled with me picking up and some just run when you get close, so spraying them on the roost is a good idea. *They roost like they are supposed to*