We hit 25 below zero (yes, that's Fairenheit) last weekend and my birds did just fine. I didn't add any supplemental heat either.
I knew the cold was coming and did as much reading as I could about the cold. I finally made the decision to just leave them as is. I brought their water inside so...
Finished the coop and run this weekend and the girls are absolutely loving their new home. I had no idea how to build a coop so after a lot of reading on this site and checking out pics of some of your coops this is what I came up with. I placed the boxes on the outside so we could gather eggs...