DE is diatomateous earth. Most people would use Sevin, but I don't like using pesticides. I hear that diatomateous earth is effective, but you have to keep at it. I didn't find any mites out there today, but I think I will sprinkle it on top of the shavings in all the nest boxes so that it comes into direct contact with the chickens. I probably should dust all the chickens, but that would be a huge chore (ours are never handled, normally). I'm only going to do that if mite evidence persists!