For the past 3 months one of my chickens has been acting odd. She will be fine and happy, have good poop, fly and run around, but then another day she will be lethargic, wont eat, only drink, poops white liquid. Then the next day everything is fine, good poop, eats and drinks, but then 4 days later the same thing happens. Over the past 3 months she hasnt layed many eggs though. Not sure what I should do.