I learned the hard way just how vindictive horse flies can be when I swatted at one while on a family vacation in Florida. Enraged, it started chasing me and even after I'd jumped in the car and closed the door, it followed us for 3 miles, flying alongside the backseat window so it could stare into my eyes. Terrifying.
Luckily I lost my horse fly when we hit the highway (although I actually wouldn't be that surprised if it had somehow made its way to Portland and was holed up in a motel plotting its revenge), but if they do catch you, my dad says the pain of their bite is "similar to being stabbed with a railroad spike."
