This is the first time I've dealt with poultry lice. I didn't put DE in my coop a couple times over winter as I ran out and bam! Now everyone has nasty chicken lice! I haven't brought in any new birds for a couple years, all of my younger chickens were hatched here on the farm, so it must have come from wild animals. I've sprayed them with neem oil 5 times and it doesn't seem to be working. They look terrible, with broken feathers and bald patches of skin. I even lost two of my young layers. I can see the lice on them. I've cleaned the coop several times, and gave them a dust bath with 2 parts sand, 2 parts wood ash and 1 part DE. I have 65 chickens, so giving them all a bath isn't really feasible. Who else has dealt with these nasty buggers and what worked for you?