And if they are bumblebees, then why would anybody want to get rid of them?
They're not aggressive, and pollinate plenty of garden plants. If you want to reduce the chance of being stung, avoid wearing blue - especially loose fitting blue clothes.
I remember being in the south island a few years back and having around 50 bumblebees around us in our camp site. They didn't attack or sting us just chilled landed on us once or twice.