I have a nest of what I believe to be Polistes exclamans that live under the eve of my house by my door in a nest they built this year. At some point today, though, they picked up and moved to an empty nest from a different species of wasp that was built last year that is hanging in my door frame over the door. I don't know of anything that happened to the nest, and it is still hanging there.

Has anyone heard of an entire nest of wasps picking up and moving to an old nest or know why one might do something like that?