Our chickens have got lice and / or mites (I'm not sure exactly how to tell the difference, but as far as I can tell the treatments are the same anyway,) and I wanted to try DE before buying anything chemical. I know some people swear by it, and some people say it does nothing, some say it helps prevent but not treat, and some say it has treated the worst ever cases fantastically. So we thought we'd give it a shot first and bought some food grade DE at the feed store. I've dusted their nest boxes, floor of the coop and run, and favourite dust bathing spots around the yard. So here are my questions: I know I need to re-dust after rain, but if it stays dry, how often should I dust, and how long should I be expecting to need to do this for before getting results / being done? Also, the nice lady at the feed store told me to dust the chickens themselves with DE after they go to roost at night, but I can't find anywhere on the internet that says to do that. Everything says to dust the vicinity with no mention of applying it to the chickens themselves. Other treatments mention putting it directly on the birds, but nothing I have found concerning DE does. Should I?