How and what product would I use to dust 100s of chickens? Is this something that should be done on a regular basis or only when there is a problem... like mites? I found out that both of my farm works are complaining about itching and one said he saw little dark bugs with hairs on himself. The itching is worse at night. Now I am wondering about bird mites now. We have never dusted before. Is that appropriate for such a large amount of chickens? We are wanting to sell them to kill now, so not sure if it is even worth it. Thoughts?