We have 14 five month old mixed standard size breeds (13 hens and a rooster). They've acted like they have a people cold going through them - occasional goopy eyes in a few of them that lasts a day or two, sneezing, gaping (is that where they open their mouths wide and stretch their necks up? if so, that's what some of them do), wheezing, etc. This started going through them about 2 weeks ago. Some had it and are now better - others seeming to get it now. None of them have acted lethargic or sick other than these kind of sinus symptoms. They are all eating, drinking, playing, etc. normally. We thought it was due to cleaning the coop/allergies/ or something environmental, but my wife's worried about the one buff orpington who is doing this gaping thing pretty consistently for 36 hours or so now. I looked down her throat with a flashlight and didn't see anything in there (other than bread she was trying to eat). Off she went to continue her free-range this afternoon. It obviously bothers my wife more than the chickens, but if we should be treating them with something we probably should start before it gets worse, right? I say wait it out, but if I'm wrong..... What could it be? Do we try to treat it with something? I increased the amount of apple cider vinegar in their water this morning to see if that will help. It has been hot here (compared to the weeks before) the last 4-5 days. We had one black australorp that had just started laying (got 3 eggs over 4 or 5 days and now nothing for 3-4 days). I think that might be due to the change in weather or just cause she's a new layer. None of the others are laying yet (flock includes ameraucanas, wyandottes, sex-link, RIR, the buff orpingtons, and the australorp). So, what to do?