Once a swarm has moved into a tree or structure the honey bees must be extracted.  
The bees have built comb, are raising young, and storing honey. They will defend their
hive and not leave voluntarily.
The owner's first inclination would be to seal the entrance.  Unfortunately, the colony
will find or make another way out of the hive.  This may be into the inside of your
structure.
The owner's next inclination is to take a can of insecticide and attempt to kill the colony.
While this is possible there are consequences.  First, it is unlikely spraying  with an
off-the-shelf insecticide at the entrance will kill the colony.  The owner may kill
hundreds or even thousands of workers.  The colony will have tens of thousands of
workers so the loss of a few hundred field bees will be quickly made up.  Also, few
beekeepers will remove a colony after it has been sprayed with insecticide for fear of
contamination of themselves and their equipment.
If the owner is fortunate and persistent enough to actually kill the colony then the real
trouble begins.  Within the walls of the structure will be five to ten pounds of dead bees
and, depending on the time of year, over 100 pounds of contaminated honey.  This dead
colony must be removed.  If it is not removed, small hive beetles may move in and lay
their eggs.  This would result in a stinking mass of maggot-like larva and fermenting
honey running down the inside of walls of the structure.  Even if the small hive beetle
does not appear the bees will rot; the comb will melt; and the honey will flow.
What can you do?  First is an ounce of prevention.  Make sure there are no voids within
the walls of your home or structure.  Make sure all cracks and openings that might let
honey bees into your home or structure are caulked.  Finally, if you see a swarm
outside your structure call a beekeeper immediately.  It is better to catch the swarm
before it moves into your home.
If you have a colony in the walls of your structure call a beekeeper first.  Once a colony
has been sprayed with an insecticide, most beekeepers will not remove the colony. If
you believe you have a colony in your structure in Montgomery County, Pulaski
County, or  the City of Radford in Virginia, call us immediately at  
(540) 577-4699 for a consultation.
Honey bees swarm in the southwestern Virginia region from about late March to July
depending on weather conditions.  Honey bee swarms will cling to trees, fences,
mailboxes or any other structure.  The swarm may be as small as a grapefruit or as
large as a beach ball.  

Swarms should be removed within 24 hours of their arrival before they find a
permanent location.  Swarms that remain in one location for more than 24 hours start to
become "dry" swarms.  They have consumed much of the honey they brought with
them.  "Dry" swarms are hungry and will become increasingly defensive.

After 24 to 72 hours the swarm will move into a void within a tree or structure. This
may be your house or building.  If the swarm moves into a structure the removal of the
colony is considered an extraction.  Bees that have established themselves inside any
type of structure are not "swarms." They are colonies.

If  you believe you have a honey bee swarm on your property in Montgomery County,
Pulaski County, or  the City of Radford in Virginia, call us immediately at  
(540) 577-4699.
Hunter Apiaries
2111 Pleasant Hill Drive
Pulaski, Virginia 24301
Email: apiscustos@hunterapiaries.com
Honey Bee Extraction is not cheap.  
An ounce of prevention is worth a pound of cure.
Swarm Collection
Honey Bee Extraction