Washington state is home to several wasp species that residents encounter regularly, from yellowjackets crashing late-summer barbecues to paper wasps building nests under eaves. The most common are western yellowjackets, German wasps, bald-faced hornets, and two species of paper wasp. Knowing which species you’re dealing with helps you decide whether to leave a nest alone or take action.
Species You’re Most Likely to See
The wasps buzzing around your food at a picnic are almost certainly yellowjackets. Three species cause the most trouble in Washington: the western yellowjacket, the German wasp, and the common yellowjacket. All three scavenge for meat and sugary drinks, which is why they show up uninvited to outdoor meals. Workers are about half an inch long, stocky, and marked with yellow and black (or white and black) bands.
The German wasp has become especially widespread across Washington. It favors nesting inside wall voids, attics, and other parts of buildings, making it a persistent urban pest. Western and common yellowjackets typically nest underground in old rodent burrows or soil cavities, though they’ll also use wall voids if the opportunity is there.
Paper wasps are longer and more slender than yellowjackets, reaching about three-quarters of an inch with noticeably long, dangling legs. Washington has two common species. The native golden paper wasp is easy to tell apart from yellowjackets thanks to its yellow-and-brown coloring, and it frequently overwinters in attics. The European paper wasp, an introduced species, has become abundant throughout the state and is trickier to identify because its color pattern closely mimics a yellowjacket. It nests readily on and inside human-made structures and is especially common in suburban neighborhoods.
Two other species build conspicuous aerial nests. The bald-faced hornet (actually a type of yellowjacket despite the name) and the aerial yellowjacket both construct large, enclosed paper nests in trees or hanging from building eaves. Bald-faced hornets are black and white rather than yellow, making them easy to distinguish.
The Northern Giant Hornet Is Gone
If you’re searching because of the “murder hornet” headlines from a few years ago, the good news is definitive. The Washington State Department of Agriculture and the USDA officially declared the northern giant hornet eradicated from Washington and the entire United States at the end of 2024. Four nests were located and destroyed in Whatcom County in 2020 and 2021. No hornets were detected from 2022 through 2024, meeting the threshold for eradication. You do not need to watch for or report this species anymore.
When Wasps Are Active
Wasp season in Washington follows a predictable arc. Queens emerge in early spring, mate, and start small nests on their own, laying eggs and raising the first batch of workers solo. Through the summer, colonies grow rapidly as workers take over foraging and nest construction.
The real problems come in late summer and fall. By August and September, colonies are at peak size and workers become noticeably more aggressive. On warm fall days, workers are guarding new queens and males being raised for the following year, and they’re defensive about it. This aggression continues until the first hard frost kills off the colony. Only newly mated queens survive the winter, tucked away in sheltered spots to restart the cycle the next spring.
Why Wasps Are Worth Keeping Around
Before you reach for a can of spray, it’s worth knowing that wasps play a significant role in pest control across Washington’s farms and gardens. Social wasps like yellowjackets are voracious predators of caterpillars, flies, and other insects. They feed chewed-up insect protein to their larvae, consuming enormous quantities of garden pests over a season.
Parasitic wasps, a huge group of mostly tiny, non-stinging species, are even more valuable. A parasitoid wasp introduced from Europe in the mid-1980s controls the filbert aphid so effectively across the Pacific Northwest that it saves hazelnut growers an estimated $400,000 per year. Another parasitoid wasp introduced in the late 1990s dramatically reduced damage from the apple ermine moth. More recently, the samurai wasp, a natural enemy of the brown marmorated stink bug, was found established in Vancouver, Washington in 2015 and is helping suppress that destructive pest. Federal researchers have also approved release of parasitic wasps targeting spotted-wing drosophila, a fruit fly that devastates berry crops in the region.
A nest tucked away in a corner of your yard that isn’t near foot traffic or doorways is generally doing you a favor.
Telling Yellowjackets From Paper Wasps
This distinction matters because paper wasps are far less aggressive and their nests are much easier to deal with. Here’s how to tell them apart:
- Body shape: Yellowjackets are short and stocky. Paper wasps are slender with a narrow waist and long legs that trail visibly in flight.
- Nest style: Yellowjackets build enclosed nests, either underground or inside wall cavities, with a single entrance hole. Paper wasps build open, umbrella-shaped nests where you can see the honeycomb cells from below.
- Behavior around food: Yellowjackets aggressively scavenge human food, especially meat and sugary drinks. Paper wasps rarely bother with your plate.
- Color caveat: The European paper wasp looks strikingly similar to a yellowjacket in coloring. Check the body shape and nest type rather than relying on color alone.
Dealing With Nests
Location determines urgency more than species does. A nest in a tree 20 feet from your patio is a non-issue. A yellowjacket colony in the ground next to your front steps is a genuine safety concern, especially for children and anyone with a known allergy to stings.
For ground-nesting yellowjackets, the safest approach is to treat the nest entrance at dusk or dawn, when temperatures are cool and the colony is least active. Dust formulations labeled for wasp control work well because returning workers track the material into the nest. Never pour gasoline into a ground nest, a surprisingly common and dangerous approach that contaminates soil and creates a fire hazard.
Aerial nests from bald-faced hornets or aerial yellowjackets high in a tree can usually be left alone. These colonies die with the first hard frost and won’t reuse the nest. If an aerial nest is attached to your house near a window or door, a professional removal is the safer bet. Disturbing a large yellowjacket colony can provoke dozens of stings in seconds, and unlike bees, each wasp can sting multiple times.
Paper wasp nests on eaves or porch ceilings are small enough to knock down with a long stick at night when the wasps are dormant, or you can use a pressurized wasp spray from a safe distance. Early spring is the ideal time to remove paper wasp nests, when the queen is alone and the colony is tiny.
What to Do About a Sting
A normal sting causes pain, swelling, and redness right at the site. Wash the area with soap and water and apply ice to bring down swelling. The discomfort typically fades within a few hours to a day.
A small percentage of people develop a systemic allergic reaction, and the warning signs are distinct from normal sting pain. Watch for hives or swelling in areas away from the sting site, abdominal cramping, nausea or vomiting, tightness in the chest, difficulty breathing, or swelling of the tongue or throat. These symptoms indicate a serious allergic reaction that requires immediate emergency care.
Anaphylaxis, the most severe reaction, can develop within minutes. It may cause a sharp drop in blood pressure, dizziness, or loss of consciousness. Anyone who carries a prescribed epinephrine auto-injector should use it immediately and call 911. If you’ve had a systemic reaction to a wasp sting in the past, the risk of a similar or worse reaction with future stings is significant, and carrying an auto-injector becomes essential.
Reducing Encounters in Late Summer
August through October is when yellowjacket conflicts peak in Washington. A few practical steps make a real difference. Keep sugary drinks covered or in cups with lids when eating outside. Don’t leave pet food outdoors. Pick up fallen fruit from trees in your yard, since fermenting fruit is a powerful attractant. Traps baited with meat (early season) or sugar water (late season) can reduce the number of scavenging workers around a patio, though they won’t eliminate a colony.
If yellowjackets are entering your house, they’re likely nesting in a wall void. Sealing the entrance hole while the colony is active is a mistake: the wasps will chew through interior drywall to find an alternate exit, sending them into your living space. Either treat the colony first or wait until after a killing frost, then seal the opening.