I have the answer. I once purchased some birds that had these very small brown mite. It looked like dirt around their vent, there were so many. Now Sevin Dust can kill the common mite and lice, but these couldn't be killed. I dust, I'd spray and two weeks later repeat, but they would never vanish. Then one poultry showman told me the trick - it's called Frontline Spray. It comes in an 8 oz. spray bottle. It costs around $30 a bottle. Squirt once or twice on the vent , then once under the feathers onto its back skin. A bottle will service an entire flock for a long time so the cost is worth it. This is the ONLY thing I have every found to get rid of all bugs. You can use it on your dogs and cats ( that's what its actually for). No need to spray your entire chicken house because lice and mite live on flesh. If they can't get on your animals they won't survive. Frontline will do the trick.
