we're down to just under 13 hours of daylight here in northern colorado. it's light around 6:30 and dark around 7:15. our production has gone down to where we're getting about 5 to 6 eggs a day on average. couple of weeks ago we were getting 8 to 9 a day on average. can't think of anything different that would affect them other than shorter days. they appear healthy, are eating and drinking normal amounts, and in general are happy chickens. what gives?