My cochin rooster and my broody hen with 4 three day old chicks both have lice and mites in the feathers around their vents. My 5 other chickens show no signs of having them because they dust bathe in DE and ash everyday. The cochin doesn't dust bathe and the broody hen wouldn't leave her eggs to dust. I would like to dust them all with poultry dust containing .25 pyrethrin. Is it safe to eat their eggs once dusted and can I dust the hen that is sitting on her chicks. If so do I need to dust the chicks as well. Should I then spray the inside of the coop with liquid seven? I have looked really hard and I don't see any mites or lice in the coop. I know they can hide during the day but I've also read posts where people can see them on the walls of their coops.