Turns out it's a small cluster of pavement ants from the outside coming into the inside of the building. On closer inspection, I noticed winged ones, while the workers were holding them down.
They haven't flown yet (although one was flying, I have doubts that it really mated), and I can't imagine they would fly inside anyways. Is it wishful thinking that they would have nuptial flight inside of a small office building?
This is in south east Illinois.
Edited by starcraftjunkie, July 20 2020 - 5:03 AM.