This was inside a rotted log section used for a seat. It cracked last time I sat on it, so I kicked it the other day, and it fell apart, the core stayed up, though, and attached to it was a hornet's nest!

That same day in about 5 hours they had sealed up the nest.

About a week later it rained 2.2 inches, and the nest fell off the stump.

Even a week later, though, they are still utilizing the nest even though it's on the ground. I assume they're trying to hatch all the pupas before moving on.