This poor chick was looking listless, not moving, and had its eyes half closed.  NOT normal chick behavior.  Upon looking at its bottom, I could see a hard blob of poo clogging the vent.  Time to get to work cleaning and unclogging! This picture was taken right after the first bit was unclogged and she was feeling some relief.  I didn't think to take a picture of the hardened feces---I was in fast action mode, here!