I volunteered to supply bees for the observation hive at the Steuben County Fair, the oldest continuous fair in the United States (they are very proud of that). I had a little colony in a four frame nuc. No brood at all, but when I looked, the frames were packed with eggs. Apparently a new queen just starting to lay. I put them into the observation hive. There weren't enough bees for the hive so they couldn't maintain proper temperature. They ate the eggs, the glass fogged up, and they wouldn't or couldn't take any sugar syrup for the two weeks they were confined.
As soon as I brought them home, I opened the entrance. A few tumbled out and the rest of the colony looked damp. I noticed fecal material on the frames and soon around the floor below the observation hive.
I thought the bees were in the process of dying, Then, Suddenly! They were gone! Here's what their domicile for the last 3 weeks looked like after they absconded. You would move out, too. Look at all the brown spots—bee poop.