People have kept Honey Bees for thousands of years, in order to exploit their honey. As part of their reproductive life cycle, every year between April and June the old queen will leave the beehive and take several thousand worker bees with her, in order to set up brand-new colony far from the beehive. This process is known as swarming.
It is throughout this process that the bees become alarming humans. Having left the beehive they come to rest in trees, bushes etc. whilst the queen sends scouts to locate suitable long-term living quarters. The worker bees will cling around the queen in a huge clump numbering around 30000 - 50000. They might occasionally rest for a number of days before relocating and shouldn't be approached. In this situation we are typically able to gather the bees alive. However we are commonly called upon to deal with a swarm which has found long-term resting place inside the structure of a building, usually the chimney breast or a wall cavity.
In this situation we would need to destroy them in the same way as destroying a wasp's nest. If left to become established, they will generate roughly 150 pounds of honey annually. This build up could eventually trigger structural building damage, with documented instances of chimneys collapsing under the weight.
Bumble Bees are definitely NOT a pest. If you see a nest in your garden please don't make contact asking us to destroy it, we will certainly not! Bumble Bees are meant to have nests outdoors. They are a non-aggressive species and won't sting you unless their nest is threatened. If you are frightened steer clear from it, no credible pest controller will destroy a nest needlessly.