All 13 of my chickens have "gone inside" everyday sometimes before the sun goes down with out fail for 8 months! Tonight about an hour after dark, I went out to lock up the run and shut the little door to the coop, both of my Columbian Wyandottes were outside huddled together (it's cold and snowing here in Colorado) next to the door but not going inside? They were startled to see me and when I stepped inside the run, they quickly went inside??? It was the strangest thing ever. What on earth would keep them from going inside? Everyone else was already inside and settled in some even sleeping already.