This noisy alarm won’t turn off until you retrieve the propeller and replace it on the base. Which means you have to get out of bed and search for it. How ingeniously irritating is that? And you won’t be able to walk across the room in zombified-autopilot mode like you do when you try the old put-the-alarm-clock-over-there ploy, because the pesky propeller can land anywhere. Aargh!
From Firebox.com