Honey Bee, Nuisance: Nests and Swarms

Honey bees are valuable pollinators of fruits and vegetable crops and providers of honey and bees wax.  Crops pollinated by honey bees and other insects contributed $29 billion to farm income in 2010 (Cornell Chronicle) and honey produced in the U.S. was worth $309.14 million in 2019.  (Statisa.com)

To learn more about benefits of honey bees or how to become a beekeeper go to www.IowaHoneyProducers.org

In spite of the benefits of honey bees and our desire to protect and promote these valuable pollinators, there are occasions when honey bees are undesirable or present a threat.

Nests in Walls

Honey bees may establish a nest inside the wall of the house or other building causing a nuisance, a health hazard and a potential threat to the structure. However, not all “bees” that nest in the wall are honey bees.  Recent experience suggests that approximately 90% of the inquiries we receive about “bees” in the ground or in a house wall are not honey bees, but rather are yellowjacket wasps.  Honey bees and yellowjackets are nearly identical in size, shape, general appearance and behavior.  It is easy to confuse the two insects but they can be distinguished by noting that honey bees are fuzzy and golden brown; yellowjacket wasps are shiny yellow with black markings.

Honey bee colonies in wall or attic voids are a much more serious problem than yellowjacket wasps. Yellowjacket colonies are annual and the wasps will disappear in the winter with or without treatment. Honey bee nests may last for many years without treatment and will contain honey stored inside the walls. Honey and wax inside a wall void can ruin walls and ceilings if it is not removed.  Honey bee colonies in the wall may increase the risk of being stung.

An experienced beekeeper may be able to save the bees by removing or trapping and relocating bees that have nested inside a wall.  Trapping honey bees from a wall may take several weeks and there may a fee for time and materials.  It may be necessary to open the wall to remove the bees and honey.  After carefully confirming that the insects are honey bees and not yellowjacket wasps, contact the Iowa Honey Producers Association for names of local beekeepers who may be able to help remove the honey bees.  www.iowahoneyproducers.org  If the insects are yellowjacket wasps, see our online article for information about wasp control, or contact a local pest management professional. https://hortnews.extension.iastate.edu/yellowjacket-wasp

If the bees are an immediate threat or if it is not possible to salvage the honey bee colonies from wall voids then extermination with an insecticide may be necessary.  This can be a do-it-yourself project or you can hire an exterminator to treat the colony.  Many pest control companies prefer not the control stinging insects and may claim it is illegal to kill honey bees.  The Iowa Bee Rule prohibits spraying insecticide in fields where bees are foraging, and vandalism or wanton destruction of bee hives is illegal.  Killing honey bees that are a pest on your property is not against the law.

Apply an insecticide dust or wasp & hornet aerosol foam into the nest opening at night. DO NOT PLUG THE ENTRANCE HOLE while the honey bees are active.  Bees will find another exit and may end up inside the house.  Spraying the nest entrance is not always effective since the comb may be located far from the opening.  Try repeated applications, or, as a last resort, dismantle the wall to reach the bees.  If the wall is dismantled and the colony and bees exposed, a detergent solution spray will kill bees that can be sprayed directly.  To make a detergent solution, mix one cup of liquid dishwashing detergent per gallon of water.

Remove and discard the comb and honey after the bees are killed. Do not salvage these materials if the colony was treated with insecticide. If the nest is not removed, the comb may be attractive to scavengers, or the wax may melt and leak honey. 

Honey Bee Swarms

Swarming is a natural part of the development of a honey bee colony. Swarming is a method of propagation that occurs in response to crowding within the colony. Swarming is an advantage to the bees but is a distinct disadvantage for beekeepers. Consequently, beekeepers manage hives to reduce the incidence of swarming to the extent possible. Swarming usually occurs in late spring and early summer and begins in the warmer hours of the day.

Honey bee swarms may contain several hundred to several thousand worker bees, a few drones and one queen. Swarming bees fly around briefly and then cluster on a tree limb, shrub or other object. Clusters usually remain stationary for an hour to a few days, depending on weather and the time needed to find a new nest site by scouting bees. When a suitable location for the new colony is found, such as a hollow tree, the cluster breaks up and flies to it.

Honey bee swarms are not highly dangerous under most circumstances. Swarming honey bees feed prior to swarming, reducing their ability to sting. Further, bees away from the vicinity of their nest (offspring and food stores) are less defensive and are unlikely to sting unless provoked.

In most situations when a honey bee swarm is found on a tree, shrub or house you do not need to do anything. Swarms are temporary and the bees will move on if you patiently ignore them. Stay back and keep others away from the swarm, but feel free to admire and appreciate the bees from a safe distance.

Only if a serious health threat is present because of the location of the swarm, such as in a highly traveled public area, should you need to do anything with a cluster. An experienced beekeeper may be willing to gather the swarm and relocate it for you. Some beekeepers collect swarms and add them to their apiary. Others are willing to relocate swarms as a public service and may rightfully charge a fee. To locate a beekeeper willing to capture swarms check with local authorities such as pest control operators, police and fire departments or contact the Iowa Honey Producers Association at www.iowahoneyproducers.org

As a last resort, you can spray a swarm of bees with soapy water or synthetic insecticide. Wait until after dark if possible. Soapy water sprays (up to 1 cup of liquid dishwashing detergent in a gallon of water) are preferred because the bees die peacefully; aerosol wasp and hornet sprays are more likely to irritate and agitate the bees before they die, increasing the chances of being stung. Spraying a honey bee swarm is a risky operation because of the large number of bees.