Ok here is my advise I have battled this for years and have tried all sorts of things. For the chickens 7 dust is best and when all the fleas are off apply the petroleum jelly, even if you think they are gone because trust me they are not wait till it gets real hot out. As for the coop and yard if you let them out is to TOTALLY submerge the ground with water. I flood out my pens and the surrounding area so the ground is about a foot deep of wetness. I know this sounds silly but I have tried 7 dust, malathyon, flea sprays, and I eve had a company come out and I still have them. I noticed today they are coming back inforce my daughter has baby ones crawling on her now. This is such a pain in the ___ to deal with. Those of you that have never dealt with this have no idea it is not a normal flea it once it's on you it's there to stay till you pluck it out. Your normal things to take care of fleas do not take care of this. I had a black chicken that was given to me 4 years ago and she died when I looked closely at her I learned of my now ongoing problem I truely believe these sticktights litterally sucked the life out of her. They blended into her so I never noticed. Shame on me never again will I be so blind I hope what I have written could help someone and if anyone could offer advise on how to take care of the coop and yard problem that would be great because they now jump on my dogs and me and my kids they even sometimes get on the goat.