Thanks for the replies. I imagine that it is just due to the shorten days, which is a bummer because this winter is probably setting back my spring chicks from starting to lay. Thanks for the article about supplemental light, I'll do some more reading about lengthening the days, but I feel okay...
I have a flock of 8 chickens, and 2 are older than the rest. The 2 that are older are a leghorn and red, and have been laying an egg a day since mid August, so for about 4 months. The other 6 I raised as chicks and are about ~5.5 months old and 1 barred rock started laying 2 days ago.Hooray...