I went though a chicken lice problem. The dusting helped. Right now you need to check the chickens in the dark. Go out about couple of hours after dark with a strong flashlight and look for your parasite. Check the vents area and every where else you can think of. I don't thing you chicken would be alive if it was stick fleas, the took out two flocks I know of here in the south, but they can travel. And she had a nice red wattle....good luck I know your frustration. r