Hi, my chickens are just over a year. In the spring I noticed that some of them were losing feathers on their heads. Then a couple had missing feathers on their backs. I just figured it was a molt. But now it is August and the feathers are just not growing back. It appears the ones around the bald spots are broken. And most of the flock now have missing /broken feathers on their backs. We had a rooster but got rid of it around 6-7 weeks ago. They have greatly decreased their laying, so I figured maybe mites. I've studied their bald spots pretty good and do not see anything. I power washed the coop and let it dry thoroughly and put DE in it (how much? I just sprinkled it around) and used pine chips. Any ideas of how I can find out what's wrong? Everyone is acting normal. I did sprinkle them good with poultry dust and gave them some wood ash for a dust bath. (but it rained.... should I put this inside?