One of my chickens started limping yesterday. It still hangs with the flock and eats/drinks, but if it tries to run or walk it limps. If it runs it makes a squaking noise each step. I am trying to figure out what could have caused it. I don't see any would, but I can't get that close and its dark now. If some bone is broke or fractured, is that likely to heal? What else could cause that? There were no loose feathers to be found in the coop area so I don't think they were attacked and its pretty secure over night.