And man oh man do those things move fast! We were renovating a two bedroom cottage, and had painted the wall and the trim around the exterior door just the week before.
The next week, I had noticed that every time I went inside and slammed the door there was a bunch of something flying around outside.
I figured it out without getting stung, and what it was was the wasps or hornets had entered where the trim meets the siding of the cottage around the door trim. You could hear them in the wall if you put your ear up against the inside paneling right next to the door. So, I got this hornet killer can of spray, and went up to the outside frame and sprayed into the hole where I saw them coming in and out. Then I stepped back quickly, in case any of them came out, but I did not notice that at the very top of the door was a guard or something. I saw it at the same time it launched itself in a straight line towards me, about 10 to 15 feet away. The whole thing took a split second, but I could tell it was headed for my left hand, so I swatted my left hand with my right hand, but not before it had stung me. The whole thing took such a tiny amount of time, that I was amazed that it had the time to get that stinger into my hand.
It was no big deal, as it hurt for a little bit, and the spot where I was stung did not swell up very much (maybe because I moved so fast in swatting the little b____r away. )
Next time, I am going to stand back and spray, because this particular can has a long shooting spray which you can aim very precisely and yet stand quite a ways away. I will still probably have to run, however.
Yet another hazard in cottage country! Never had this problem when I was growing up back in southern Alberta. As a kid, we used to beat the heck out of big giant yellow jacket nests with a stick, and they would all come swarming out, but they seemed to be too stupid to realize that the kid with the stick was the problem. Ontario bees are smarter, I guess.