I recently read that with the time change when the days get shorter it's like not enough daylight for them. So they say to put a heat lamp with your chickens and they will think the daylight is the same length and will lay eggs again. Thy also could be broody but I doubt all of them are. The chickens need at least so many daylight hours I think 12 hours to lay an egg but the daylight hanged to shorter so you would do best to put a heat lamp or two with them. Hope this helps.