I think these paper wasps were in a nest grown in the iron skillet you can see at the top of picture. I had set it out as the base for a possible bird nest. I posted this picture at bugguide.net to find out about the unusual activity and received this reply: I watch my entryway daily to see what insects have arrived and this morning I discovered this group near a small cast iron skillet I had set out on top of a column as a possible bird nest site. I'm glad I didn't take down the skillet so I could clean out the nesting material! I couldn't get far enough away from this spot with my 300mm lens to fit all the wasps in the frame. I posted this picture at bugguide.net asking about this activity and received this response: Mature nests often "overflow" because so many individuals hatch out at the same time. It is quite common for them to gather in a sheltered spot near the nest. Cool photo of this! A nest at my house sort of did the same thing www.youtube.com/watch?v=K7nnfv-AdJg