My chickens have fleas around their eyes, combs. How can I get rid of them? I have 16 chickens and all of them have them except some have it worst than others. I’ve lost a few chickens because of this infestation. Any suggestions? I’ve been using a mixture of water, dawn and vegetable oil to spray their faces which works for a little while but then the fleas come back. I’ve also spread diatomaceous around the coop. Even tried limestone and nothing seems to get rid of them. Help!