I have 19 hens and no roosters all of them are coming up on 2 years old. One of my chicken has some big bald spots on her back that are getting worse and I'm looking for some advice. I'm gonna be setting up a separate area for her so I can seperate her from the flock but if there's something I can give her or a balm or something I can put on the area that'll help the feather's grow back I'd be interested. They've gotten bald spots here and there from pecking each other but I noticed a few weeks ago the bald areas on her back were getting bigger and it wasn't going away on its own. To the point I'm concerned about frostbite with it getting colder. Any advice would be helpful, thank you.