You're mean for killing them. All you have to do is talk to them and explain that you want to be their friend. Swarms of bees or wasps are surprisingly open to honest conversation. If you visit with them often, eventually they'll become tame and they'll start following you around in a line. You'll be walking along with a long line of bees/wasps following you. They'll protect you from bad guys too.
I have a few bees in particular who are really good pals of mine. Stingy likes to do tricks. I'll say "spin Stingy spin" and he'll fly around really fast. Then he sits on my shoulder and nuzzles my neck.