When a beehive gets too large the hive splits. Half of the bee colony (2,000-6,000 bees) move out traveling as a swarm, creating a visually bizarre phenomenon. While traveling to start their new home, bees may rest on a bush or tree temporarily (up to 3 days).
A bee swarm in this phase is usually about the size of a football or basket ball. If the swarm of bees is new, they will be non aggressive. This is because they have no home or domain to defend yet and there is no honey or young to protect. It may be suggested that the best way to get rid of these bees is to leave them alone. Perhaps about 90% of the time the bees will move along within a few days. Bothering or disrupting bees may frustrate their plans and could cause them to stay longer than normal.
If you are trying to get rid of an established hive on a tree or bush and you live in a non-africanized honeybee removal state, you may also look for a beekeeper. If you live in a county where africanized bees exist, you can pay to have them removed alive as opposed to extermination. Exterminators get rid of the bees but often charge more than a bee removal company that removes the bees alive. If you try to get rid of the bees yourself, make sure no people or pets are close by, plan your escape route, and expect to be stung! If the bee hive is established, it is considered unwise to attempt to remove it yourself.