Bees often seek shelter in dark, enclosed areas; to that end, hives are commonly found in tree hollows. If a bee colony gets too large, it will break off into swarms, which can result in a major bee infestation in your yard. When getting rid of bees from a tree, take all safety precautions to avoid getting stung or angering the swarm. If the problem is too immense you may need to contact a beekeeper or pest control specialist to remove the bees if you can't do so yourself.
Locate where the beehive and source of the bees is on the tree. Keep your children or pets away from the area until you eliminate the bees.
Purchase an aerosol spray that is specifically for killing bees from your local home and garden retailer. Make sure that it is specified on the label that the spray will kill honey bees.
Spray any bees that you see outside in your yard, by your garden or near the tree with the aerosol spray. Wear protective gloves when using the spray and then wait at least one day to allow the bees to return to the hive.
Purchase a spray concentrate insecticide for controlling bees if you still see bees flying around near the tree. Apply as directed on the label and then wait another 24 hours for the hive in the tree to be affected.
Reapply the insecticide directly to the hive each day as directed on the label and make sure to wear protective clothing. Continue applying the insecticide until there are no signs of bees, and eventually the hive will fall to the ground.