One of my 8 girls has not been acting right for the past couple of weeks. At first, I attributed it to the fact that she was possibly being picked on by the rest of the flock. She has been "hiding" by going into corners, behind the food container etc. She molted with the rest, but now doesn't look as "full" as the others. Today I noticed she is walking with a very slow and pronounced high step. I've had all hens in this flock for 3 years plus so there has been no introduction of other hens. They are not free-rangers so they are very protected in their own space. I don't know if she contracted something and, if so, how does that happen. Hopefully, someone can give me some direction. She seems very sad. Thank you!