Washington is one of the more interesting states in the country for wasps, for two reasons. First, the Cascade Range splits it into two climates that produce genuinely different wasp seasons — cool, wet, marine western Washington on one side and hot, dry eastern Washington on the other. Second, Washington was the entry point for the northern giant hornet (“murder hornet”), the invasive species that dominated headlines in 2020 and has since been eradicated from the United States.
For non-aggressive wasps I've had great luck spraying nests with this Spectracide wasp remover in the evening. For a nest up high in an eave, soffit, or tree, this Gotcha pole adapter clamps onto the can so you can spray from the end of an extension pole and treat the nest from 10+ feet away instead of standing right under it. And for anything aggressive I wear this ridiculous-looking upper torso beekeeping suit and keep my distance. It seems silly, but trust me, I learned the hard way.
This guide covers the wasp species Washington homeowners actually encounter, how to tell them apart, when each one peaks in your part of the state, and what to do about a nest. For a nationwide overview, see our wasps by state regional guide; for physical identification features that apply to any species, see the complete wasp identification guide.
If you are trying to identify something buzzing around your Washington yard right now, it is almost certainly one of these five:
| What you’re seeing | Likely species | Nest location | Risk level |
|---|---|---|---|
| Fast yellow-and-black wasp raiding your food or pop can | Western yellowjacket | Underground, in a hole in the lawn or bank | High — the state’s main stinging problem |
| Yellow-and-black wasp flying in and out of a gap in siding | German yellowjacket | Wall voids, attics, crawlspaces | High, and hard to reach |
| Big black-and-white wasp with a football-shaped gray nest in a tree | Bald-faced hornet | Aerial paper nest in shrubs and trees | High if the nest is disturbed |
| Slender wasp with dangling legs and an umbrella-shaped nest under the eaves | European paper wasp | Small open-comb nest under eaves, in pipes, in gas grills | Moderate — defends the nest only |
| Skinny black or metallic-blue wasp building small mud tubes | Mud dauber | Mud cells under eaves, in sheds and carports | Very low — beneficial spider hunter |
Everything else — sand wasps, cuckoo wasps, ichneumon wasps, velvet ants — is a much rarer sighting and rarely a homeowner problem.
Most Washington wasp advice fails because it treats the state as one place. It isn’t. Your side of the mountains changes the timing, the species mix, and the nesting behavior.
Western Washington (Seattle, Tacoma, Everett, Bellingham, Olympia, Vancouver): Cool, wet springs slow colony growth dramatically. Overwintered queens emerge in April and May, but heavy spring rain drowns a meaningful share of newly started ground nests, so colonies build later and the real nuisance period arrives late. Yellowjacket complaints peak from mid-August through early October, and mild marine winters mean activity can trail into November before sustained frost ends it. Wall-void nesting is common here because damp soil and abundant older wood-framed housing give German yellowjackets easy access.
Eastern Washington (Spokane, Yakima, Tri-Cities, Wenatchee, Walla Walla): Warmer, drier, and more continental. Colonies get going earlier and grow faster in dry soil, and peak nuisance arrives sooner — roughly late July through September. First frost typically comes in early to mid-October, several weeks ahead of the Puget Sound lowlands, so the season ends more abruptly. Mud daubers and native paper wasps are noticeably more common east of the mountains, where dry sunny walls and open ground suit them.
Practical takeaway: if you live west of the Cascades, September is your highest-risk month for accidental stings. East of the Cascades, August is. See when are wasps most active for the underlying colony-growth pattern.
Nearly every serious wasp complaint in Washington involves a yellowjacket. Three species matter.
The default pest yellowjacket of the Pacific Northwest and the species behind most Washington picnic, barbecue, and orchard incidents.
Identification: About half an inch long, bright yellow with sharp black bands, a completely hairless glossy body, and a distinct yellow ring around each eye. It flies fast and directly, and holds its legs tucked in flight rather than dangling.
Nesting: Underground, almost always in an abandoned rodent burrow, a gap under a stump, or a cavity in a bank or retaining wall. A single entrance hole with a steady two-way stream of wasps is the giveaway. Mature colonies commonly hold 1,500–4,000 workers by September.
Why it matters: Western yellowjackets are scavengers as well as predators. Late in the season, when their natural insect prey thins out, they switch hard toward protein and sugar — which is exactly why they show up at your barbecue, your open soda can, and your fallen apples in late summer. They also sting without much provocation once the colony is large.
For nest identification and treatment specifics, see our guides on underground wasp nests and ground wasps.
An introduced European species that has become firmly established in urban western Washington and is the one most likely to end up inside your house.
Identification: Very similar to the western yellowjacket at a glance — same size, same colors. The reliable difference is nesting behavior, not appearance.
Nesting: Structural voids. Wall cavities, attic spaces, soffits, crawlspaces, and gaps behind siding. Colonies inside heated buildings can grow larger and persist later into the year than outdoor nests.
Why it matters: A German yellowjacket nest in a wall is the hardest common wasp problem in Washington to resolve safely. Never plug the entrance hole — trapped workers will chew laterally through drywall and end up inside living space. This is one of the few Washington wasp scenarios where professional treatment is clearly the right call. If wasps are appearing indoors, see how are wasps getting in my house.
Often mistaken for a bald-faced hornet because it builds a similar enclosed gray paper nest, but it is yellow and black rather than black and white.
Nesting: Rounded enclosed paper nests hung in shrubs, low tree branches, under decks, and against house walls, usually 3–15 feet off the ground. Colonies are smaller than ground yellowjacket colonies — typically a few hundred workers.
Why it matters: These nests are frequently discovered mid-hedge-trimming, which is the worst possible way to find one. Walk your shrubs and eaves before you start yard work in August and September.
Our yellow jacket complete guide covers all three in more depth, including yellow jacket sting treatment.
The bald-faced hornet (Dolichovespula maculata) is common statewide and is the species behind the big gray “paper football” nests Washingtonians notice in maples, alders, and Douglas firs in late summer.
Identification: Large — three-quarters of an inch or more — and unmistakably black with bold ivory-white markings on the face and the tip of the abdomen. No yellow anywhere.
Nesting: A fully enclosed, layered gray paper nest with a single entrance near the bottom, usually well off the ground. Nests reach basketball size by September and hold 400–700 workers.
Behavior: Bald-faced hornets are calm away from the nest and genuinely dangerous near it. They defend a much wider perimeter than paper wasps and will pursue an intruder some distance. Keep at least 15 feet away from an occupied nest.
Despite the name, this is not a true hornet — it is a large aerial-nesting yellowjacket relative. See our bald-faced hornet identification guide for details.
Introduced to the Pacific Northwest in the 1990s, the European paper wasp is now the paper wasp most Washington homeowners see, particularly in and around cities.
Identification: Slender, roughly half an inch, with crisp yellow-and-black banding that fools people into calling it a yellowjacket. The tells are the bright orange antennae, the yellow legs that dangle loosely in flight, and the slow, floating flight style. A yellowjacket flies fast with its legs tucked; a paper wasp drifts with its legs hanging.
Nesting: Small open-comb nests shaped like an upside-down umbrella, with visible hexagonal cells and no paper envelope. It nests in an unusually wide range of sheltered spots — under eaves and deck rails, but also inside gas grills, patio umbrellas, mailboxes, downspouts, exposed pipe ends, and playground equipment. Colonies stay small, typically under 100 wasps.
Why it matters: European paper wasps are far less aggressive than yellowjackets and will not bother you at a picnic. The risk is proximity: because they nest in places people put their hands, most Washington paper wasp stings happen when someone opens a grill lid or grabs a railing without looking.
See the European paper wasp guide and paper wasps complete guide.
Washington’s native Polistes species — most commonly the golden paper wasp, Polistes aurifer — are more frequent east of the Cascades. They are slightly larger, with more brown and amber tones and less crisp yellow patterning than the European species. Behavior and nest structure are essentially the same, and so is the management approach: removing paper wasp nests early in the season, when the nest is small, is far easier and safer than doing it in September.
Black-and-yellow mud daubers (Sceliphron caementarium) and blue mud daubers (Chalybion californicum) occur throughout Washington and are most conspicuous east of the Cascades, where dry sunny walls suit them.
Identification: Very long, thread-thin waist; either black with yellow leg markings or an entirely metallic blue-black body. They move slowly and deliberately and are almost impossible to confuse with a yellowjacket once you have seen the waist.
Nesting: Small mud tubes or lumpy mud cells plastered under eaves, in carports, sheds, barns, and unused equipment.
Why to leave them: Mud daubers are solitary, non-defensive, and provision their nests almost entirely with spiders — including black widows. They essentially never sting homeowners. If the mud is cosmetically unacceptable, scrape it off after the season with a putty knife and hose the surface down. See the mud dauber complete guide.
This is the single most common Washington-specific wasp question, so here is the current status.
The northern giant hornet (Vespa mandarinia), widely called the “murder hornet” in the press and formerly known as the Asian giant hornet, was first confirmed in the United States in Whatcom County, Washington, in December 2019. The Washington State Department of Agriculture ran a multi-year trapping, tracking, and nest-eradication program; several nests were located and destroyed near Blaine in 2020 and 2021. The last confirmed Washington detection was in 2021, and after three subsequent years with no detections, USDA and Washington State agriculture officials declared the species eradicated from the United States in December 2024.
In practical terms: if you are in Washington today and you see a very large hornet, it is not a northern giant hornet. It is almost certainly one of these:
Washington officials still ask the public to report suspected sightings, because early detection is what made the eradication possible and British Columbia remains under surveillance. If you have a clear photo of something you believe is a giant hornet, report it to the WSDA Hornet Watch program at agr.wa.gov/hornets. Do not attempt to capture it.
For the full background, see our Asian giant hornet complete guide.
Worth noting: the European hornet (Vespa crabro), the large brown-and-yellow true hornet that genuinely lives in the eastern United States, is not established in Washington. Reports of “European hornets” in the state are almost always bald-faced hornets or large queens.
| Period | Western Washington | Eastern Washington |
|---|---|---|
| March–April | Queens begin emerging on the first warm dry days; single large wasps scouting eaves and banks | Queens emerge slightly later than the coast in cold years but build faster once started |
| May–June | Nests founded; wet weather destroys many ground nests; colonies still tiny | Colonies establish quickly in dry soil; paper wasp nests visible under eaves |
| July | Colonies scaling up; first noticeable yellowjacket activity | Activity ramping hard; aerial nests become visible |
| August | Activity climbing; hedge-trimming discoveries common | Peak season — largest colonies, maximum scavenging and sting risk |
| September | Peak season — maximum colonies, heavy scavenging at fruit and outdoor food | Still very active; declining after the first cold nights |
| October | Declining; still active during warm afternoons | First frosts end most activity |
| November–February | Colonies die off; only mated queens overwinter; nests are abandoned | Colonies dead; abandoned nests safe to remove |
The single most important Washington-specific detail on this calendar: the harvest overlap. Washington’s home apple, pear, plum, and grape crops drop fruit in exactly the weeks that yellowjacket colonies hit maximum size. Fermenting windfall fruit is one of the strongest late-season yellowjacket attractants there is. Rake and bag fallen fruit at least weekly from mid-August onward — removing the food source does more for backyard yellowjacket pressure than spraying individual wasps ever will.
For the biology behind the die-off, see where do wasps go in the winter and what temperature do wasps stop flying.
Leave it alone if: it belongs to a mud dauber, it is a small paper wasp nest away from doors and walkways, or it is late October and the colony is already collapsing. Wasps are significant predators of caterpillars, flies, and aphids, and an out-of-the-way nest is doing your garden a favor.
Handle it yourself only if: the nest is small, reachable from the ground without a ladder, clearly a paper wasp nest, and nobody in the household has a sting allergy. Treat after full dark when all foragers have returned, and never from a ladder — a startled reaction on a ladder turns a sting into a fall, which is by far the more serious injury.
Call a licensed professional if: the nest is inside a wall, soffit, attic, or crawlspace; it is a bald-faced hornet nest; it is an established underground yellowjacket colony near a walkway or play area; it requires a ladder; or anyone at the property has a known venom allergy.
Never: plug a wall-void nest entrance, pour gasoline or other fuel into a ground nest, or burn a nest. Sealing a nest in redirects the colony into your living space; fuel and fire are illegal in most circumstances, contaminate soil, and start structure fires.
Timing note for Washington: because western Washington springs are cool and wet, small paper wasp nests remain easy to remove much later into June than they would be in the Southeast. That extended low-risk window is worth using — walk your eaves in late May and early June.
If you are stung, see our wasp sting treatment guide. Seek emergency care immediately for hives away from the sting site, throat tightness, difficulty breathing, or dizziness.
Roughly 600 native bee species live in Washington, and a large share of “wasp” reports turn out to be bees. Misidentification leads to unnecessary treatment of pollinators, so it is worth knowing the difference.
The general rule: bees are visibly hairy, thicker-bodied, and carry pollen; wasps are smooth, glossy, and sharply waisted. See difference between bees and wasps and the bee vs wasp vs hornet guide for a full comparison.
Honey bees (Apis mellifera) are golden-brown and fuzzy, and cluster in managed hives or occasionally in wall cavities and hollow trees. A honey bee colony in a structure should be handled by a beekeeper for live removal, not exterminated.
Bumble bees (Bombus spp.) are large, round, and densely furred. Several species are common in Washington yards, and they nest in small colonies in ground cavities, compost piles, and insulation. They are extremely reluctant to sting. The western bumble bee (Bombus occidentalis) was once one of the most abundant bumble bees in the Pacific Northwest and has declined sharply — it is now a species of conservation concern. Leave bumble bee nests alone whenever you can; they die out naturally by fall.
Mason bees (Osmia lignaria, the blue orchard bee) are small, stout, and metallic blue-black. They are solitary, effectively stingless in practice, and outstanding orchard pollinators — Washington’s fruit-growing regions actively encourage them. They nest in hollow stems and drilled blocks and seal their cells with mud, which is why people sometimes confuse them with mud daubers. If you see a small metallic bee packing mud into a hole in early spring, that is a mason bee, and it is one of the most valuable insects in your yard.
Mining bees and other ground-nesting solitary bees appear in bare lawn patches in March through May, often in loose aggregations that look alarming. They are fuzzy, tan or brown, and gone within weeks. They do not sting defensively and require no action.
The wasps Washington homeowners encounter regularly are western yellowjackets (the main ground-nesting pest), German yellowjackets (which nest in wall voids), aerial yellowjackets, bald-faced hornets, European paper wasps, native golden paper wasps, and mud daubers. European hornets are not established in Washington, and northern giant hornets were eradicated from the state.
Washington’s wasp season runs roughly April through October. West of the Cascades, colonies build slowly through a cool wet spring and peak in September; east of the Cascades, they build faster and peak in August. Activity ends with sustained frost — early to mid-October in eastern Washington, often November in the Puget Sound lowlands.
No. Northern giant hornets were detected in Whatcom County starting in December 2019, the last Washington detection was in 2021, and USDA and state officials declared the species eradicated from the United States in December 2024. Large hornets seen in Washington today are bald-faced hornets, overwintered queens, or large solitary digger wasps. Suspected sightings can still be reported to the WSDA Hornet Watch program.
The western yellowjacket. It nests underground in lawns and banks, reaches colony sizes of several thousand workers by late summer, scavenges aggressively at human food, and stings with little provocation once the colony is mature. German yellowjackets are comparably aggressive and harder to treat because they nest inside structures.
Two things line up. Yellowjacket colonies reach maximum size in late summer, and at the same time their natural insect prey declines, pushing workers to scavenge human food and fallen fruit. In Washington this coincides with home fruit harvest, so fermenting windfall apples, pears, and plums concentrate wasps in residential yards precisely when colonies are largest and most defensive.
Yes. All workers and males die once temperatures stay near or below freezing, and nests are permanently abandoned — wasps never reuse an old nest. Only mated queens survive, hibernating individually under bark, in woodpiles, in leaf litter, and in sheds and attics. Because western Washington winters are mild, colonies there may linger into November, but by December the nests are empty and safe to remove.
The species list is largely the same, but the timing and the mix differ. Seattle and the rest of western Washington see more structural nesting by German yellowjackets and a later peak in September, driven by cool wet springs and mild falls. Spokane and eastern Washington see faster colony growth in dry soil, an August peak, an earlier hard frost, and noticeably more mud daubers and native paper wasps. See our Seattle wasp guide for city-specific detail.
Small paper wasp nests reachable from the ground can be handled by a homeowner after dark, provided nobody has a sting allergy. Everything else — bald-faced hornet nests, established underground yellowjacket colonies, and any nest inside a wall, soffit, attic, or crawlspace — warrants a licensed professional. Never seal a wall-void nest entrance; trapped workers chew inward and end up in living space.
For a region-by-region overview of which wasps live where in the US, see our Wasps by State: Regional Identification & Seasonal Activity Guide. For species-by-species physical identification, see the Wasp Identification Guide.
Washington and the Pacific Northwest:
Species guides for the wasps on this page:
Nests, seasons, and safety: