In Ohio here I have seen heated nipple bucket waterers for chickens advertised. I have power to my duck coops and have 7 heated water bowls for them. Right now we have a foot of snow on the ground and it will get down to -7 F tonight so I am glad that they have them.Hahahaha, yeah, AI is really helpful for SOME things. I have heard a solar powered water agitator (meant to keep mosquitoes from breeding in bird baths) helps during daylight hours but I just use an electric de-icer myself.
Oh, and I have a nipple bucket waterer in the coop. It doesn't change the humidity if you already have plenty of ventilation.
