Funny, I was searching for something else regarding chicks and ended up finding this. What I ended up doing was to give the hen a bath with a mild flea shampoo. I did it using warm water with the chicks nearby under a heat lamp and used a blow dryer to dry her off quickly, which she actually loved. She seemed much happier afterwards and I made a dust bath with sand for her to use afterwards, which she did. That way I was able to get rid of her bugs without exposing the chicks to any chemicals. Here it is seven years later--she's 11 years old with a new batch of chicks, and I think I will be doing the same thing once the temps get hotter in the next couple of days.