If you want to hang out with a bunch of bees, you'd better be prepared for a little pain.
Mario Padilla, a honeybee researcher at Penn State University, can usually tell when his hives are getting agitated. But he's already been stung three times today. And he's about to get it again.
"I got stung!" Padilla says, half-laughing. "And that was a sting that was not even an invited sting. That was an I-was-minding-my-own-business sting."