4 days ago one of my 14 week old polish chicks just dropped dead. It was totally fine in the morning and when I checked on them at 4:30ish it was dead. Now, my other Polish is acting weird. When I went to lock up the coop tonight he/she was still in the run and was just standing there hanging his head to one side. I brought it in and fed it yogurt and sugar water. It ate and drank OK but after about 45 minutes inside with me it wouldn't even stand up. I'm afraid it will be dead by morning. What could this be? I'm hoping it was just a hereditary thing with these two Polish but worry there's something going around that is going to kill off my whole flock. Here are some pics.