I've never had to deal with those (yet). One thing I seemed to notice about the hornets: When I was around them they could swarm all around me, and did, but never hurt me. They had 4 nests inside a small 10'x12' shed and I could walk right in. But I didn't feel any fear of them, and I was careful not to do anything to harm them, like accidentally bang anything against one of their nests. But a few other people went over there who had a natural fear of them and got stung right away. It was almost as if they could sense the fear and they went right after it!
On the bright side, I had many thousands of dollars of stuff in that shed, and there was a local burglar living 2 houses away that burglarized almost every house in the neighborhood (when they caught him, he still had a lot of the stuff in his possession that he hadn't fenced yet), he knew I had stuff in there and any 5 year old kid could have easily broken in, yet in about 4 years of opportunity he never attempted it. Yep, fear of hornets! :-D