Well, our neighborhood is obviously a prime nesting area for cicada killers. They look impressive, because they are a big wasp. Most of the females are about 1 1/2", but we seem to get what I call "Godzilla Cicada Killer Women" who are 2 1/4" long and THICK.
Those are not too common, but they do happen. I actually measured one to find out how long it was.
Page about cicada killers:http://aggiehorticulture.tamu.edu/galveston/beneficial3_cicada_killer_wasp.htm
Males do not have a stinger, females do. Now, the males act really aggressive to anything that comes around: other males, dragonflies, the kids. The females are not supposed to be aggressive at all. Maybe it is the population density or maybe this is a slightly different offshoot of the species (hence the big Godzilla females), but we have had a problem with aggressive females.
So, I have been doing control in our section of the neighborhood. My weapon is a wiffle ball bat and I have gotten quite good with it. When I was a kid, we used to go after carpenter bees (they bored into the sides of the barn) with old broom handles, so I have prior experience at this sort of thing.
Anyway, wiffle ball bat in hand, I make war with the cicada killers. The males are not bad, because they tend to "attack" a certain way by flying back and forth, but not changing altitude. A good level swing takes them out. The females, especially the mean ones, are another matter. They can be hard to hit and, once you annoy one, it seems like both she and several males will come after you. I wouldn't mind the males, because they can't sting, but they often make me lose track of the female, she with the stinger. Ever see a full grown man dueling with half a dozen angry cicada killers? I move back and forth, wiffle ball blade dancing in the air in short hard chops, always turning to keep my front to them.
If somebody in the neighborhood has a video camera, I am going to end up on YouTube.