What do I do and who do I call if there's a swarm?
If you discover a swarm of honey bees you should first confirm that they are honey bees before calling a swarm collector.
Wasps, hornets and other pests should be dealt with by a pest controller. Beekeepers and swarm collectors do not usually charge a fee but they can sell the collected bees or add them to their stock to produce more honey.
Follow the steps that the BBKA desribe here regarding swarm removal.