I noticed today that one of my hens is missing a few wing feathers. I wasn't concerned - 'tis molting season, after all. Then I realized that there was blood where the feathers had been. Right after that, another hen came over to her and becked at the bloody area. It isn't a huge area and isn't very bloody but I want to prevent problems. So I separated her so none of the other hens can get to her. She won't be able to free-range with them, but I'm concerned that they will eventually peck her to death if I don't keep them away from her. What would cause the blood initially? Is there anything else I need to do besides separating her from the others?