Biologists have found a way to listen to the sounds in the hive to determine when a queen is preparing to swarm. Swarming is common behaviour in honey bees. It is the way that bees expand their numbers. When a hive feels that it is running out of space the queen prepares to leave with a portion of the bees in the hive. The hive produces a new queen and when that is ready the swarm leaves in search for a new space to grow. A swarm is a very gentile group of bees. Their honey stomachs are full and they have nothing to defend. Beekeepers clearly want to control swarming because when a hive swarms it reduces production. Click here to learn more about how to mitigate swarming. If you are an urban beekeeper a swarm of bees is very intimidating to the neighbours and creates a PR nightmare.