We've had chickens for roughly 3 weeks now. 1 naked neck rooster and 4 hens. 2 hens are 4 months old other 2 are pullets, 1 pullet we have an issue with all of a sudden this morning she stayed in the roost and could left her head. Shed slowly Bob it over and over almost lifeless but still standing. Help me any advice would help. We have her currently secluded from other chickens