I have a flock of 4 hens, two just started laying. We also have 4 younger chicks and 3 ducks, I don't know if that matters. The older chickens have always gotten along. We've had them since they were 4-6 weeks. Just last week they've started alienating one of the chickens. She's always off by herself now and they won't let her eat with them. There's no pecking or attacking her which is good. Anyone have any idea why this happens or how to get her accepted back in the flock?