Annette, I wonder if that was poisoning or not. When the wintertime "shutdown" is forthcoming, many, many of the summer bees die and you will see many, many bees dead out the front of the colony. Sometimes it is really hard to know if it is just nature, or if it has been a direct result of something awful. The fact that your colony is appearing strong, surely makes me think it was just the last of the summer bees dieing. Remember, if a few frames of bees emerge at the same time, they are pretty much going to die at the same time. Keep that chin up, I personally only think it is winter dying off bees. Keep us posted on how this colony is, would love to hear more. Have that wonderful and most awesome day, healthy good days. Cindi