I have 7 chickens and for the first time this winter I am having problems with frostbite. When the coop was built this fall, I included lots of ventilation, vents that can be closed in winter to eliminate drafts, but others that are open, above their head. Plus their door, which I don't close as the coop is in the yard. I have blocked it on a few occasions to reduce excess draft on really cold nights, but there is still ventilation and the chickens can actually get out in the morning. Earlier this winter it had gotten as low as 2 degrees here, back in November before my chickens had their full coats and they did fine. It has repeatedly dropped into the low teens, with no sign of frostbite. This past week we have again had really cold temps, with windchills. On the really cold days I attempted to keep the chickens in their coops, but when I went to check on them they bum-rushed me and I had to just leave them out. One day it was -10 so it was recommended that I bring them in the garage since my coop isn't heated. Probably a good thing because my rooster showed frostbite that afternoon before I brought him in. He patrols the run so he does not stay well inside the windbreaks like the rest. I read many recommendations of putting vaseline on combs so since it was going to be a week of under 20 degrees and my rooster already had a tiny spot of frostbite, I rubbed vaseline into all their combs. Now, with the days in the upper 20's and the nights in the teens I have what looks like the beginning of frostbite or frostbite (whitish or yellow tips on the comb) on almost all their combs. Except the two that I did not get to put vaseline on (they are very tough to catch but also have smaller combs, so I wasn't too worried about them. Two did coat their combs with mud one day, I think that added to the problem. And my rooster is showing some dusky black in places as well, but I can't tell if it is dirt or frostbite. He is hard to catch except at night on the roost so I can't check that out until tonight. I don't typically keep water in the coop. I use the deep litter method and turn the straw every few days. I have never seen condensation. The straw looks pretty dry. Pine chips to absorb moisture as well. They appear to be getting the frostbite during the day, because I notice it at night when I get home. Until it warms up this weekend I check them regularly. Bringing them into the garage (35-40 degrees) just for the night was okay but getting them back out was a bit traumatic for them. They were good and warm and awake and in an unfamiliar area and suddenly I had them flying into walls. Help! Suggestions? Thanks!