I went down to the coop this morning to give my chickens some fresh water and food and I noticed that my 6 month old Buff Orpington rooster had these little black dots/bumps on his comb and wattles. Is that frostbite or something else? They were kind of hard and wouldn't come off......well one I picked of a little and it came off. It has been in the 30s and 20s this past week but I haven't put any heat in the coop like a heat lamp or anything. It almost looks like ashes or something but they haven't been outside in several days and there's no ashes in the barn/coop. I put petroleum jelly/vaseline on it but I don't know if it helped. Should I put vaseline/petroleum jelly on them every day to prevent frostbite or just when they get it? Will it prevent it? Should I put it on the Buff Orpington hens.....should I put it on the Brahma hens and the Brahma rooster???