My laying hens all have been sneezing around since it got winter - for about like 2 months now. They don't have any secretions from their eyes or swelling anywhere. There is nothing dripping from the nostrils, but when they sneeze, sometimes a bit of white gunk flies off. They behave perfectly normal, eat, drink and move around. They are not laying presently, but I attributed that to winter and shorter daylight hours. Today I noticed that one of the hens was sneezing a lot more than usual, almost every minute and sometimes in a salvo. But she was also behaving normally and when I let them out, she was quite energetic and took to chasing the other chickens around (she's No. 2 in the command chain and loves chasing the others). Should I be worried about her newly increased sneezing or the general sneeziness of my flock? Do something? Is it an infection? Or maybe a sort of allergy? I've got a moisture problem in the coop which could possibly lead to mold. Whatever it is, the new rooster I have added to the flock has also caught it - he's started sneezing as well after a few days with them. My Bantam pair which is in a different coop doesn't sneeze so far.