Pest identification guide
Paper Wasps: Open Nests, Identification & Help
An exposed, umbrella-like comb under an eave can be a paper-wasp nest. Its location and the chance of disturbance matter when deciding on a response.
Property-specific help across Southwestern Ontario and the 401 corridor.
Recognise the pest
How to identify paper wasps
Polistes wasps are known as paper wasps or umbrella wasps. They build an upside-down, open-cell nest, with a single layer of cells suspended from a stalk and no outer covering. Eaves and older buildings are among the listed sites.
That is a useful contrast with the enclosed, multi-layered paper nests built by yellowjackets and bald-faced hornets. However, nest appearance is a clue rather than permission to approach: paper wasps vary, and some types build in cavities or on vertical surfaces.
Where to look and what to record
Use accessible observations to guide an inspection. Do not disturb a nest, handle an animal or enter a hazardous area to obtain evidence.
Under eaves and sheltered building edges
These are common paper-wasp nest spots. Report the position from a safe distance.
Older buildings and concealed cavities
Old buildings are common nest sites, and some paper wasps nest inside cavities. A nest need not always be fully visible.
Near fruit trees and food activity
Paper wasps feed on insect larvae and rotting fruit. A feeding wasp and the nest may not be in the same place.
Behaviour and why it matters
Paper wasps can be beneficial because they feed on other insects. They defend the nest when disturbed, and getting too close can provoke them. A small nest should not be treated as harmless simply because few wasps are visible.
Mated females survive the winter and the social cycle develops again in spring. Paper-wasp types also differ in how they use nests, so don't assume an old-looking nest is empty or that every nest behaves the same way.
An inspection-led approach
Practical next steps
These steps follow an integrated pest management (IPM) approach: identify the pest, find the source, then treat. They are not instructions for selecting or applying a pesticide.
Avoid disturbing the nest
Do not touch it or move closer for identification. Describe its position, whether the cells are exposed and whether wasps are entering or leaving.
Explain how the area is used
Tell the technician whether the nest is beside a door, walkway, work area or another routinely occupied location. Where the nest is matters as much as what built it.
Confirm access and the response
Ask whether the nest can be assessed safely and what intervention is appropriate. The scope and any follow-up should be confirmed for the actual nest and property.
Paper Wasps: common questions
What does a paper-wasp nest look like?
A paper-wasp nest is a single exposed comb with open cells, often hanging from a stalk under an eave. Some paper-wasp types build differently, though.
Is every enclosed paper nest a paper-wasp nest of this type?
No. The open umbrella-like comb is quite different from the covered, layered nests of yellowjackets and bald-faced hornets. Identification should consider both the insect and the nest.
Can paper wasps sting if the nest is small?
Yes. Paper wasps get defensive when the nest is disturbed. A low visible wasp count is not an assurance that approaching or touching it is safe.
Should every paper-wasp sighting be treated?
Many stinging insects are beneficial, so it is worth asking whether a nest needs to be dealt with at all. Nest location, use of the area and the likelihood of disturbance inform that decision.
Compare related pest guides
General information and safety notice
This guide is not a site inspection, confirmed pest identification, pesticide-use instruction, or medical, veterinary or legal advice. Do not choose, mix or apply a pesticide based on this page. Follow the current product label and your technician's written preparation and aftercare instructions. Avoid disturbing nests, handling wildlife or contaminated material. Treatment scope, timing, follow-up and any warranty are subject to the service terms confirmed for your property.
Help for your property
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Tell us what you have seen, where it appears and how long it has been happening. We will discuss the options and confirm the service scope.