Some people are allergic to bee stings, and yellow jacket stings are among the most venomous, according to my observations. A friend of mine was stung in the forehead by one, and her head swelled up like a pumpkin. She looked like something out of a horror movie for about two days. My neighbor was stung by one and his whole body swelled up, and he had trouble breathing for hours. I have worked on slate roofs since 1968 and have never been stung by any bee except yellow jackets and honey bees, and only once or twice. I am not allergic to them and was once stung by 17 yellow jackets as a teenager with no adverse reaction. But now I spot them before they spot me and I avoid them if I can. If I can’t avoid them, I spray them with hornet spray if I can get close enough to spray the nest itself. It does no good to just spray the bees because there are thousands of them, but if you can knock out the nest the remaining live bees will usually leave you alone (they become demoralized and disoriented after the queen has died).
Residential roof here.
