I have 16 laying hens and this is their second winter. Last year we didn't notice much of a drop in egg production, but this year, we're getting only 4-6 eggs a WEEK for the last 2 weeks! We have an open air coop, but their roosting area is blocked from excess wind. We have a heated water bowl that keeps their water just warm enough not to freeze. I actually had to buy eggs from the grocery store for my Christmas baking!! Any ideas?