For a few years, my home office had been in the finished basement of a split-level house in the suburbs. The desk faced the window, and as I worked, my back was to the rest of the basement. One Sunday afternoon in the summer, I was trying to figure out how some software worked and for a time was in the zone and oblivious to what was going on around me. After a few hours, I caught a glimpse of something out of the corner of my eye: it was a wasp landing on the window. That jolted me back to reality and as I was rolling up a magazine (after trying to find a printing industry trade magazine that was thick enough to actually kill a wasp, which was a challenge), I heard a weird noise from behind. I turned, and saw that the basement was completely aswarm with wasps that had somehow made a nest in the electrical junction box. I grabbed the laptop, ran upstairs, and called Terminix.
Needless to say, that pretty much killed productivity for the rest of the day. Fortunately, it was a Sunday.