It takes 9 mph to out run a fly. Any less, and the pesky like creatures appear to slipstream, hover, land and generally do all that fussing and buzzing that flies do. They apparently see us, in all our sweaty glory, as large, two-wheeled, moving piles of dog waste.
If you pause at the top of climb to admire the view, there they are. Stop to change a flat, and thereâ€™s a hat load of them. Itâ€™s as if youâ€™re loitering in a fly hatchery. But the moment you set off again, gain a bit of momentum, and hit the magic 9 mph, thatâ€™s it, theyâ€™re blown away, unable to keep up with your blistering turn of speed. Try it some time.
So we did a bit of scientific research, and yes it appears that the average speed of a common fly is just shy of 5mph. So a top-flight, lycra-clad fly – pardon the image – may peak out at 7.5 mph.
Just for the record, the drawing above shows the average speeds for some more of our flying friends. Oh, and you read that right at the bottom there. A Horsefly is positively supersonic – with an average speed of 90.1mph! Donâ€™t believe us? Look it up.
Thanks to 18 Miles Per Hour for this Universal Truth.