When I had my infestation, I did mix some permethrin a little on the heavy side. and sprayed thoroughly inside the coops. It will take a few weekly sprayings. I did spray the birds with a weaker solution and also put the poultry dust in the nest boxes. I have shade/rain tables in all of the pens and during the hotter period during the day, the birds get under the tables so I sprayed under the tables and put some dust under them too. My suggestion would be to do a weekly spraying for about a month and then see how much better the birds will be. Good luck...
This is what I use.
https://www.tractorsupply.com/tsc/p...ivestock-and-premise-spray-32-oz?cm_vc=-10005
This is what I use.
https://www.tractorsupply.com/tsc/p...ivestock-and-premise-spray-32-oz?cm_vc=-10005