We have 3 gold sex links, 3 RIR, 2 barred rocks, and one bramha bantam. Our chicks are approximately 10 weeks old. They live in an enclosed coop, and have a 12X12 very secure, covered yard we let them out in. Monday dawned sunny and bright, so we opened the door to the yard for them. Mid morning, we had a sudden thunderstorm. Lots of wind, lightning, sleet, and the temp took a nosedive. We went out as soon as we could to find that the chicks were piled in the corner of the coop with feathers fluffed, obviously cold. We locked them up and got the heat lamp going and in an hour or so, they seemed fine. Monday evening, when doing the evening chores, I noticed that one of our barred rocks was sneezing. Tuesday morning everyone looked fine and I didn't hear any more sneezing. Tuesday afternoon I went out to check on them and see them in the sun and they were in the coop hiding out. I believe they may have been visited by a hawk during the day. Anyway, now they act all freaked out anytime they hear a bird of any sort calling. They will only go out in the yard for a second before running like mad for the coop. Tuesday evening we find that all of the gold sex links, and a RIR are sneezing up a storm and wiping their beaks. This morning, I stayed out for about a half an hour and only heard one sneeze from the RIR, but one of the gold sex links has a bit of runny poop. Other than that, they are eating, drinking, and acting nervous. Questions: 1. Would you worry about the sneezing? We have been putting ACV in their water. 2. Could it be stress? The chill and then the visit by something that has them freaked out? Sorry so long. My DH says they are just chickens and to quit worrying about them, but I can't! Thanks!