Well… unless you are allergic, like I am. But, again, the best course is to leave them alone or remove yourself from their vacinity. I never kill a bee on purpose. And, if it's bumble bees, like the ones nesting in my porch railing, I welcome them because they keep the wasps away – to which creatures sting I'm even more allergic. I almost died once from a wasp sting and had to be rushed to the hospital. The couple of times I've been stung by bees (playing in clover as a kid), my foot swelled up like you wouldn't believe; For a few days, I had to take a course of antihistimines and keep my foot elevated above my heart until the swelling went down.