Honey Bee

Encyclopedia Article

Nests in Walls

Exposed Bee Comb on Rock. Photo by Gary Koehle
Exposed Bee Comb on Rock.
Photo by Gary Koehle

Honey bees may establish a nest inside the wall of the house or other building causing a nuisance, a health hazard and a serious threat to the structure. However, not all “bees” that nest in the wall are honey bees. It is much more likely that the insects that look and behave like honey bees and are nesting inside the house wall or foundation are yellowjacket wasps. It is easy to confuse the two insects so careful examination rather than assumption based on distant observation is essential.

Honey bees and yellowjackets are nearly identical in size, shape, general appearance and behavior. Color is the easiest distinguishing characteristic. Honey bees are fuzzy and golden brown. Yellowjackets are shiny and lemon yellow with black markings. If you are not sure of the pest identification collect several dead specimens and take them to your county extension office or request ISU Extension pamphlet PM- 1671, “Wasp and Bee Control.”

Closer Look at Exposed Bee Comb on Rock. Photo by Gary Koehler
Closer Look at Exposed Bee Comb on Rock.
Photo by Gary Koehler

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. The honey can ruin walls and ceilings if it is not removed.

If it is not possible to salvage the honey bee colonies from wall voids then extermination with an insecticide may be necessary.  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 wax may melt or be riddled by wax moth larvae and begin to leak honey. If there is much honey it can seep through interior walls, leaving a permanent stain. Bees from other colonies and scavenger insects may be nuisances as long as the honey remains.


Honey bee swarm. Photo by Jessica Edler.
Honey bee swarm. Photo by Jessica Edler.

Honey bees are valuable and provide tremendous benefits, specifically pollination, honey and wax. However there are times and places where honey bees create an annoyance and a nuisance, and for sting-sensitive individuals, a health threat. One such incidence is when honey bees swarm.

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, such as a hollow tree, is found 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.

Close Up Look at Winter-killed Bee Brood. Photo by Gary Koehler
Close Up Look at Winter-killed Bee Brood.
Photo by Gary Koehler

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 and the local extension office. There is no central or state-wide registry of beekeepers that will capture swarms. You can also contact your district officer of 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. 

Do you live in Iowa and have an insect you would like identified?

The Iowa State University Plant & Insect Diagnostic Clinic will identify your insect, provide information on what it eats, life cycle, and if it is a pest the best ways to manage them.  Please see our website for current forms, fees, and instructions on preserving and mailing insects.   

Contact information for each states diagnostic laboratory for U.S. residents.  If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic