It's a tradition at Microsoft that when someone leaves for a while, their office is vandalized in one way or another. Sometimes it is something big like moving the office into the hall or covering it in post-it notes. Other times, it's something more subtle. For me, it was subtle. I returned from a short trip to California and all seemed well in my office. Then I heard it. A short high pitched squeal. Almost as if one of my monitors was not quite in sync. Seemingly every 15-20 minutes the same noise or something similar but shorter pierced the room. I tried to localize the sound but it was difficult because it was so short and came unexpectedly. After 2 days (much of which I wasn't in my office), I had it narrowed down to one corner but hadn't found it yet. I'd looked inside the computers, underneath the desk, in the legs of the desk. Still nothing. I knew it was something my team had done because of their reactions. When I was in 1:1s with them and the sound happened, they ignored it. Still, I hadn't been able to figure out quite what it was. This evening they revealed it to me. I think I would have found it within another day or so but it was hidden well. It turns out they had put a small circuit board called an Annoy-a-tron under the leg of my desk. It puts out a 2 kHz or 12 kHz sound at random intervals. Well done guys. My hat is off to you.