Why was he doing it?

The thought of a painful bee sting can discourage humans from getting too close. But apparently butterflies don't fear them at all. I watched a butterfly attack a bee like he was Ali. Ali's catch phrase I float like a butterfly but I sting like a bee kept running through my mind as I watched him. I couldn't figure out why the butterfly was bugging him anyways. There were plenty of other flowers around that he could have went to for pollen. Was he trying to save some for other butterflies? Or was he just bored. Perhaps he knew that I would enjoy watching him.