I have some of my month old bantam chicks that are separated from the rest of the flock...in a brooder...they are hunched over sneezing a little bit...and I saw one with a bubble from its nose...The night time temps have gotten a little cooler than usual and while we were gone on vac we didn't have the light set to come on. Could this be the problem or is it something else. (food is medicated chick starter and were vaccinated for Marek's...got them from Ideal)