I had a hen that just wasn't quite right, so I decided to worm her and dust her even though I couldn't see any mites/lice... I was amazed by the number of dead feather lice that were hiding somewhere on her.
-Kathy
Do an experiment... Dust one, put it in a covered box on white paper towels and come back in 45 minutes, you might be surprised as to how many we're actually there.
-Kathy