Our chickens have had mites as well. I don't nkow if you can look under my account name (I don't get completely how to get around), but, there is a great description of what to do and what they are, etc, and some links on those couple of threads. I looked at the Carbaryl in the feed store, but, it was Sevin for plants and not livestock. I looked specificaly for the pyrethrins, but animal grade and it was in the cow section (although it was a mite killer and it showed chickens on it...all animals). Then, follow what you listed before, but, these directions have you do it again a few times and every 7-10 days. The reason being is that all those little eggs you see on the base of the feathers will not be affected by the treatments until they hatch...then you treat again and kill the next batch between layings. My understanding is that for the initial treatments you must cover the first 21 days or so...so..treat, then 7-10 days later, treat again, and then 7-10 days later, treat once more. Then you can go much longer in between if they are symptom free. If you treat and then wait for two months they entire cycle will have started again. I am no expert, but did a lot of research when we had them. See if you can find the threads under my account and read those...lots of great information. Also, depending on where you are, it makes a difference if they are lice or mites and there is a great article on telling the difference. It does make a difference on how you treat it. Also, remember that although the DE is a great product, it has not been shown to kill the eggs and therefore is not an effective overall treatment for ridding lice. Good luck!