[Acebird]

I have a field string mower and yesterday I used it to whack all the dead weeds. Knowing of stories about weed whackers around hives I expected to get zapped but it didn't happen. I am wondering what it actually is about the weed whacker or the technique used that agitates the bees.

 

[Acebird]

and quickly passed in front of their flight path.

This may be the problem. Try moving very slowly. They have no problem getting around you but if you go quickly they may feel threatened.