My 9 week old easter egger chick is missing feathers on her back. This was not there 2 days ago. There is no bleeding or drainage. It does not appear that the others are picking on her. She is acting normally, eating, does not seem to be bothered by this or in pain. I have 9. Grace is probably a day or so older than the rest, and has been somewhat of the leader of the group, brave, friendly. I live in Illinois. This is our first time to have chickens. I have a mixed flock, received them at about 2 days old. The chicks were inside our house until 2 weeks ago when we moved them to their new coop in our back yard. They seem to have adjusted well, and like it. The run is not finished yet. They eat Purina medicated chick starter/grower and chick grit. I recently started giving them a small amount of greens, meal worms, slugs/worms as treats, but not a lot. Is this a disease, parasite? Do they molt at this age? I appreciate any advice or help.