Pest of the month:

Paper Wasp

As warmer weather arrives across Oregon, paper wasps start becoming more active around homes and businesses. In the Portland Metro, Canby, Salem, and surrounding Willamette Valley areas, spring and early summer are common times to begin spotting paper wasps building nests under eaves, rooflines, patio covers, sheds, light fixtures, and other sheltered areas.

Paper wasps are one of the more common stinging insects homeowners notice as temperatures rise. While they are not usually aggressive when left alone, they will defend their nest if it is disturbed. That makes them a concern around front doors, decks, children’s play areas, walkways, and commercial entry points.

What Are Paper Wasps?

Paper wasps get their name from the paper-like material they make by chewing wood fibers and mixing them with saliva. They build small, open-comb nests that look like an upside-down umbrella with visible hexagon-shaped cells. Unlike yellowjackets, their nests are not enclosed in a large outer shell.

Paper wasps are often seen flying with their legs hanging down, and many species are brown, reddish, yellow, or black. The European paper wasp has become especially common around human structures and is frequently found nesting on buildings and other sheltered surfaces. Paper wasp nests are usually smaller than yellowjacket or hornet nests, often with fewer than 100 workers.

Paper wasp colonies start fresh each year. Overwintering queens emerge in spring and begin constructing small nests.

The queen starts the colony on her own by building the first cells, laying eggs, and caring for the early brood.

As those first workers develop, they take over foraging and nest expansion while the queen focuses on reproduction. Colonies grow through the warm season, then decline as temperatures cool.

The current colony does not survive the cold season, though new queens can overwinter and start again the following year

Why Paper Wasps Matter Around Homes and Businesses

Paper wasps can actually be beneficial in some settings because they feed on caterpillars and other insects, which can reduce some garden and landscape pests. Oregon State University notes that paper wasps are generalist predators and often prefer caterpillars.

The problem is location.

When paper wasps build near doors, outdoor seating areas, garages, play structures, sheds, mailboxes, commercial entryways, or under eaves, the chance of accidental nest disturbance goes up. Even though they are generally less aggressive than yellowjackets, they will defend the nest when threatened. Their tendency to nest in concealed or sheltered places around structures increases the risk of close human contact.

Where Paper Wasps Commonly Nest in Oregon

In the Portland Metro and Willamette Valley, common nesting areas include:

• Roof eaves and soffits
• Porch ceilings and patio covers
• Exterior light fixtures
• Sheds and outbuildings
• Fence overhangs
• Window and door frames
• Deck rail areas
• Garages and attic vents
• Commercial storefront overhangs and service entries

Because Oregon properties often have sheltered trim lines, covered patios, and moisture-friendly spring conditions, these protected surfaces can become ideal nesting spots.

Signs You May Have Paper Wasps

Here are some common signs of paper wasp activity:

• Wasps flying in and out of the same sheltered area
• A small open nest with visible cells under an overhang
• Increased activity around eaves, porches, or exterior lighting
• Wasps hovering near doors, garages, or outdoor seating areas
• Repeated sightings in the same spot during warm afternoons

Are Paper Wasps Dangerous?

Paper wasps can sting, and social wasps defend their colony when disturbed. For most people, a sting causes immediate pain and irritation, but for those with allergies, stings can be more serious. Because only females sting, workers defending the nest are the main concern. The risk goes up when nests are hidden in high-traffic areas and are accidentally bumped or approached too closely. 

What Attracts Paper Wasps?

Paper wasps are drawn to protected nesting sites and available food sources. Conditions that may make your property more attractive include:



• Protected overhangs and rooflines
• Exterior voids and undisturbed corners
• Flowering landscapes that attract insects
• Caterpillars and other prey insects nearby
• Outdoor food or sweet drink residue
• Trash or recycling areas
• Warm, sheltered spaces around structures

What Homeowners and Businesses Can Do to Help Prevent Paper Wasps

There are several ways to reduce the chance of nesting around your home or commercial property:

Regularly inspect the structure

Check eaves, patio covers, sheds, garage entries, and light fixtures during spring and early summer so nests can be noticed before they get larger.

Knock down inactive starter nests early

Very small early nests can sometimes be found before colony growth increases. Care should be taken around any active nest.

Seal and repair conducive areas

Repair damaged trim, close unnecessary gaps, and maintain exterior fixtures and overhangs where nesting commonly starts.

Reduce food attractants

Keep outdoor eating areas clean, cover trash, and avoid leaving sugary drinks or food residue outside.

Use caution around active nests

Never disturb an active nest near doors, decks, or high-traffic areas without proper treatment and safety precautions.