1st thing to do sweetie, is clean the chicken house very very well. Clean all the poop and bedding out, and sweep every surface with a good stuff broom to get it as sparkling clean as possible, you might even get a house with a good power sprayer to wash it, and let it dry. And make sure you wear a very good dust mask, you don't want to be breathing chicken poop and lice. The lice thrive in a dirty coop.
2nd, after it's cleaned and brushed down with a broom to eliminate as much dust and poop as possible, dust everything with diatomaceous earth, (floor, walls ceiling, roosts, nest boxes,...)and in your case, maybe a lice dust as well. Get "one bite bars" from the farm supply store. They are yellow, and look like corn cobs. They desicate the rats so they don't rot, stink and attract fly's. Put the one bite bars under the floor or wherever the chickens and any other animals, like cats, can't get to them.
3rd, put new clean bedding down.
4th go in at night when the Chickie's are calm and dust each bird heavy with dte, and maybe the other lice dust.
5th Also get an old paint brush, and paint everyone's legs with bag balm. It's a medicated cream for goat's milk bags, but as an oil, and a cream it will moisturize the chickens skin, smother any scale mites, and heal any injuries. Good stuff. My mom keeps chasing me around with it, whenever I get a scratch...
6th, make sure the chickens are getting enough food, that the food isn't getting wasted all over the floor, and make sure they are getting greens. Ppl say that the store bought mash is a complete nutrition, but in my life of raising free range, I can starkly see the difference between the health of my free range that get grass and bugs, and the ones that are confined, and don't get any. Even just lawn mower clippings, or veggies from the garden.
Keep us posted.
