Our five young chickens (1.5 years old)and one older chicken haven't laid since July. Now I am noticing that one of them is molting like crazy and it's end of November. We have never had this happen before. We've let them be free range and it hasn't helped them. There has two runs, one goes under our deck, one goes out in the open. Any ideas of what this could be? We've owned chickens for about 5 years and have never had this happen. Thank you.