Am I creating a wasp hazard?

Asked April 21, 2020, 1:01 PM EDT

Hello, I am thinking of capping the top of my double-lap wooden privacy fence with sheet metal. This would result in 4" x 4" x 3/4" cavities every six inches. (There would be about 500 cavities.) The cavities would be closed at the top and sides and open at the bottom. My questions are: Would wasps build nests in a cavity only 3/4" deep, and would I be creating some of kind of an insect nuisance for myself and my neighbors? What is the minimum size cavity wasps will build nests in? Thank you!

Franklin County Kentucky

5 Responses

This likely would provide an area that paper wasps would nest. Hornets would not since they build large enclosed paper nests high in trees. Yellow jackets primarily nest in cavities, often from rodent burrows, wall cavities, open attics.

There is no minimum cavity in which paper wasps will build a nests. In natural settings, paper wasps build their nest on the bottom of tree limbs. They have taken advantage of the protection that human structures afford, nesting under eaves, gutters, and ledges, inside attics, sheds, barns, or any other structure that provides shelter.

Paper wasps are not very aggressive, unless their nests are disturbed. Their primary diet is spiders and insects, often many pests. How often paper wasps would use these fence cappings as a nesting site and whether they would create an insect nuisance or native insect habitat relies on several factors, including: Is your household or your neighbors seriously allergic to bee and wasp stings. What is your household's and your neighbor's tolerance of insects. How available food and water sources are. What the weather is that current year.

For more information on wasp biology, ecology, and management strategies, please refer to the following publications.
ENTFACT-620: Controlling Wasps, Hornets, & Yellowjackets -

Thanks for the information. I don't know that anyone nearby has a medical issue with the wasps, however, the many wasps already in the area are good at getting in homes, which terrifies some people.

ONE MORE QUESTION. Someone has suggested that in the summer it might be too hot inside these thin gauge sheet metal caps for wasps to live there. Does that sound likely? (The fence is mostly unshaded.)

A picture of one test section of the fence cap is attached. The final design would be a little shorter in height and sections would overlap to cover the entire fence. Much of the void at top could be eliminated.

With that additional information and pictures of the design, I would not think this would be an attractive nesting site for paper wasps. If the sections are overlapped, then the only major entrance would be at the ends of the fencing.

I don't think the heat would be an issues since they often nest along the roof lines of barns and sheds.

Sorry, I guess the photo is misleading. If you zoom in you may be able to see that every 6 inches there is a 4 inch gap in which the wasps can enter. The beards are overlapped, they are not edge-to-edge. Thanks.

I don't believe the 3/4" width would provide a large enough space for a suitable nesting site.