Help. Two dead hens within a week of each other. 5 months old, not unkempt-looking, no mucous, no diarrhea. No signs of illness beforehand. Free range, coop at night. First found in morning in nest box week ago. Tonight, hen lying in coop at door, looked dead, stroked her, opened eyes, went down to house to tell spouse, he went up, found her dead. The only thing that looked odd was her comb was very red. ???