I have a winter duck question. Our two 9 month old drakes live in a predator-safe pen in our yard. We live at 7,300 feet elevation in Utah and it gets rather cold here. While we have heard that ducks are fine down to -20 degrees, we notice that our boys are a bit subdued at temperatures below 15 or so. Inside their pen is a modified chicken coop that is filled with pine shavings. They sleep in there a lot (not all) of the time, and generally hang out in there when the weather is cold and windy. We made a somewhat arbitrary decision to shut the boys in the coop on nights where the low is forecast to be +10 or below. By using a remote thermometer in the coop we know that doing this adds about 10 degrees to the inside of the coop. Example; I get up in the morning and it is 6 degrees outside and about 15 or so in the coop. However, the sensor also records humidity and it can be 70-85% in the mornings after they have been shut in there for 8 hours. When I open the roof of the coop, vapor rolls out, and there is a thin coating of ice on the inside of the coop roof and walls. Is this humidity dangerous or unhealthy for the boys? Dave Holderread says "Good ventilation is essential, however, even in cold climates because ducks will fare poorly if forced to stay in stuffy, damp quarters." I have heard others say that drafty is better than damp. The coop has small vent holes in the sides and I am thinking about adding more. So the question: Is the ten degree temperature rise gained by shutting the coop door at night worth the extra humidity? It routinely gets down to zero here and occasionally dips down to -10 or even -20 on rare occasions. We could continue as usual, drill more vent holes, or just stop shutting the coop door. Thanks for any help.