Bumble bees are in critical decline in the UK - they are exceptionally gentle bees, and do not deserve the reputation many people attribute to them.
There are 24 species of bumble bee in the UK - in the last 70 years, 3 species have become extinct.
Much like honey bees, bumble bees collect nectar and pollen from flowers - they have no interest in the human population, and they will only ever sting if they feel their lives, or the safety of their nest is in jeopardy.
To be blunt - if you get stung by a bumble bee - you're either really really unlucky - or you deserved it !
Similar to honey bees, bumble bees are in decline in the UK, and should not be destroyed.
If AT ALL possible, we would urge you to leave the bumbles alone until later in the year - the colony will naturally die out, and the queen will hibernate.
You can dissuade bumbles from returning to the same site the following year by filling in the hole they used - but please make sure you leave it until the winter to fill it in - in case you entomb a living colony!
Perhaps as recompense for bunging up a potential future nest site, you could provide them with a small wooden bumblebee house in a corner of your garden - they can be purchased from garden centres, and will provide a home for a bumble nest the following year.
If you have problems with the flight path the bumbles take on the way out or back into their nest, place a small screen mesh a foot or so from the entrance - this will force the bumbles to fly up and over, hopefully avoiding you altogether.