My year old australorp keeps shaking her head (mildly and occasionally). I don't see any mites or other bugs. Any ideas? Also, do australorps usually lose the feathers around their head? I saw another flock of australorps recently that seemed to be "bald" and now mine seems to be as well. They do not seem to be growing back. I though maybe she was molting but nothing new is replacing the ones that have fallen out. Any ideas?