she could be one of the agressive ones, i've seen quite a few of them, the best way to see them is by the water source.
they fight a lot, and loose a lot-of hair, anyway this day, i was..like usual, busy, very busy :-D watching the bees drinking water, and there was this bee, running around like mad and chasing off any bee she encountered, like.."my house", she was there for at least 15 minutes, i even filmed her a bit.