Most commercial beekeepers will not collect a swarm or nest of feral honeybees. The time it takes to collect the swarm would cost a bee keeper more than the bees are worth. Most swarms in San Diego County are Africanized honey bees and the beekeeper who collected a feral swarm would have to destroy the queen in the feral colony and replace it with a European honey bee queen. If this was not done, the colony would remain Africanized and would be difficult to manage.
When honeybees swarm, they often form a cluster on a branch or other object and stay over night. These bees are usually not aggressive and will not sting if you leave them alone. The bees usually leave in a day or two if they can find a hollow space nearby to build a nest. If the bees cannot find a good nest site in a few days they will start to build honeycomb where the swarm is resting. The bees will defend their exposed nest and may sting any person or animal who comes too close. If feral honey bees begin to build a nest, you should hire a pest control company to get rid of the bees. It is dangerous when Africanized honeybees nest near a home, and removal of the colony is the responsibility of the property owner.
You should inspect the walls and roof of your home and plug any openings where honey bees might enter. Honey bees only need an opening 1/4 inch in size to enter a wall or attic. If honey bees build a nest inside your home, hire a pest control company to get rid of them. After the bees are dead, you should open the wall or roof and clean out all the wax and honey. This may require the services of a building contractor. Honey which bees have stored in their nest can leak out if bees are not present. Also, if wax is not removed, its odor will attract other feral swarms. A new swarm may make another nest in your home or another location nearby.
For more information see UC ANR Publication 8068 Bee Alert: Africanized Honey Bee Facts
By V. Lazaneo, Urban Horticulture Advisor, Emeritus, UC Cooperative Extension, August 2012