I was in the post office last Friday to pick up a parcel. From the counter, I could see back into the loading dock and sorting area. While I was waiting on the clerk to find my package, I heard birds chirping. I thought that one or more birds must have flown in the garage bay doors. I looked around at the ceiling, but didn't see any. But I could still hear the chirping.
Then, I noticed a box on a table behind the counter area; it had holes and on the side was printed, "Live Baby Chicks"

When the clerk returned, I asked what kind of stamp was on the box, but he thought I was just kidding and laughed. I didn't pursue it.
KirkS