Of course one sting is bad enough. A wasp which is in the act of defending its territory/nest/life is hardly going to give you a warning shot first. Just respect them (they deserve it) and leave them alone. Considering how many wasps we have around in summer every year, it's amazing how infrequently they sting. I tolerate wasps and just brush them away if they annoy me. I had to extirpate a wasps' nest from my porch a couple of years ago. It took several concerted attempts, all carried out by me up a ladder, wearing shorts, t-shirt and sandals. Not one sting. In fact, in my 60 years on this planet I've been stung just once by a wasp and that was when I was nine years old, and I *live* outdoors in summer. If we went around slaughtering wasps merely because they carry a sting, then I suppose we ought to be going around slaughtering all those brainless yanks who insist on carrying guns. After all, they're far more deadly.