Honey bees are valuable pollinators playing an important role in both native and agricultural crop production. Beekeepers keep bees in wooden manufactured hives, but the most common natural nest site for bees is a hollow tree or other cavity. Occasionally, honey bees may use a wall void or attic space in a house as a nesting site. In these situations, the decision to take action depends upon the circumstances. Here are some common questions asked by people who discover bees nesting within their home.
Will the bees cause any damage to my house?
NO. Honey bees will do no structural damage to a building. Unlike other pests, such as termites or carpenter bees, honey bees do not chew or eat wood. Some people choose to leave the colony alone and have had bees inside a wall for many years. If you do decide to exterminate them, any large quantities of honey left behind should be removed to avoid staining and destruction of inside walls or ceilings. The honey and nest debris may also attract other insects pests and rodents.
When did they move in?
Honey bees reproduce by swarming where part of the old colony leaves to seek a new homesite. Swarming occurs mostly during the months of Oct and Nov. If you notice bees in your house at another time of year, especially summer, chances are great that they have been there since spring and you have just now noticed them.
Can I just plug up the hole and suffocate them?
If the entrance hole is plugged, the bees will look for another exit. They may find another crack or opening or they could follow light and enter your living quarters instead through gaps in baseboard, electrical outlets or vents.
Can a beekeeper come and take out the bees?
Yes. However, removing the bees usually takes a lot of time and effort once they've moved within a wall. The value of the bees, alone, is not sufficient to justify the effort and liability of involved in removing them. Fewer and fewer beekeepers are willing to do this, and those who do, often charge a fee and may still leave the responsibility of any repairs up to the homeowner. Be sure that you agree about price and what is expected in this service. Contact your RSPCA and ask if there is a list of local beekeepers who perform this service.
Can the bees be trapped out or made to leave?
Trapping is sometimes done, but it is rarely practical because it takes several weeks and doesn't remove 100% of the bees. After one or two days in a cavity, almost no amount of prodding or trickery will cause them to leave on their own.
Why isn't simply spraying the bees sufficient to solve the problem?
A honey bee colony within a wall can be killed with insecticide by the homeowner or a licensed pest control operator. However, if the bees have been in the wall for more than a few days, wax combs and honey may already be stored within the wall. The longer the colony has been there, the greater is the likelihood that large amounts comb and honey have accumulated. There may be as much as 20 kilos of honey within a wall by the end of spring. The remaining honey and wax could eventually ferment and run down the wall or ceiling, so it should be removed after the bees are killed in the best way possible. The greatest amount of honey will likely be found at the end of spring and the least amount found at the end of winter. Large quantities of decaying bees may also attract carpet beetles which could, in turn, attack natural fibers materials (e.g., wool, fur, or silk) within the house.
How do I spray the nest?
Use an aerosol "bee and wasp" spray; the kind typically found in most lawn & garden centers or retail stores. Spray the chemical directly into the entrance hole during the evening hours, when all adults are most likely inside. If you're spraying overhead, protect yourself from any chemical mists that drift down toward you. If you need to use a ladder to reach the nest, be extremely careful. The spray may cause the bees to fly out of the nest toward you. Wear long-sleeved shirt and pants and a hat, if it makes you feel more confident. If the colony has been active in the wall for more than two or three weeks, consider opening the space to remove any wax and honey. Once the bees and nest material have been removed, fill the void with insulation, caulk or close off the entrance so that future swarms will not be attracted to the same cavity.
Why didn't the spray kill them?
The insecticide must contact the colony to be effective. Sometimes the nest area is not close to the opening. Try to locate the exact nest area by tapping the wall and listening. If necessary, a 6mm hole may be drilled into the wall to introduce the insecticide. In this case use a pesticide product that has a "crack & crevice" tool (a straw-like attachment for the nozzle that allows you to inject the chemical into the void).