If you’re a homeowner in Connecticut, you’ve almost certainly had wasps around the house, whether that’s a paper wasp nest under the deck railing, yellow jackets coming out of a hole in the lawn, or a big gray hornet nest showing up in a maple once the leaves drop. Connecticut’s wasps are typical of New England: a short, intense season that builds slowly through June and July, peaks in late August and September, and ends with the first hard freezes of October and November.
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.
Not every wasp here is a threat. Several common Connecticut species are solitary, rarely sting, and do useful work controlling caterpillars, spiders, and other pests. This guide covers the species Connecticut homeowners actually run into, how to tell them apart, when each one is most active, and how to deal with a nest safely. For a nationwide overview, see our wasps by state regional guide. For identification features that apply to any species, see the complete wasp identification guide.
| Wasp | What it looks like | Where it nests | Sting risk |
|---|---|---|---|
| Eastern yellowjacket | Small (½ in), bright yellow and black, fast, stocky | Underground, often in old rodent burrows | High: defends nest in numbers |
| German yellowjacket | Like the eastern, with black dots on the face and abdomen | Wall voids, attics, sheds, sometimes ground | High: nests hidden inside homes |
| Bald-faced hornet | Black with white face and markings, ¾ in | Large gray paper nest in trees, shrubs, eaves | High near the nest |
| European hornet | Very large (1–1.4 in), brown and yellow, flies at night | Hollow trees, barns, attics, wall voids | Moderate: defensive at nest only |
| Aerial yellowjacket | Yellowjacket-sized, yellow and black, yellow markings on face | Small gray paper nests in shrubs and under eaves | Moderate to high near the nest |
| Northern paper wasp | Slender, dark brown to reddish, dangling legs | Open umbrella comb under eaves, decks, railings | Low to moderate |
| European paper wasp | Slender, yellow and black (looks like a yellowjacket), orange antennae | Open comb in railings, grills, mailboxes, pipes | Low to moderate |
| Mud daubers | Long thin “waist,” black or metallic blue | Mud tubes and cells on walls and ceilings | Very low |
| Cicada killer | Huge (1.5 in+), black/rust with yellow bands | Burrows in sandy or bare soil | Very low |
The first three rows cause most of the sting problems in Connecticut. The bottom three rarely sting at all.
Connecticut is small, but the season still varies a bit between the colder northwest hills of Litchfield and Tolland counties and the milder shoreline from Greenwich to Stonington. The shoreline usually sees frost a week or more later than the hills, so its wasps stay active longer in fall.
| Month | What’s happening |
|---|---|
| January–March | No active colonies. Mated queens overwinter alone under bark, in woodpiles, and in wall voids and attics. A warm February day can wake one indoors. |
| April–May | Queens emerge and each one starts a new nest by herself. Paper wasp combs the size of a golf ball show up under eaves. This is the easiest time to deal with a nest. |
| June | The first workers hatch and take over foraging. Nests grow quickly. Mud daubers start building. |
| July | Yellowjacket and hornet colonies grow fast. Cicada killers appear in sandy lawns and along walkways. |
| August | Peak colony size. Ground nests get run over by lawn mowers and string trimmers, and sting calls go up. |
| September | Peak nuisance season. Colonies start raising new queens and males, workers turn to sweets, and yellow jackets crowd picnics, trash cans, apple orchards, and fall fairs. |
| October | Colonies decline. The first hard freeze (typically early to mid October in the hills, later on the coast) kills most workers. New queens leave to find winter shelter. |
| November–December | Nests are empty. Old nests are not reused. Wasps seen indoors are overwintering queens or stragglers. |
That late-summer peak is the most important fact on this page. Most Connecticut sting complaints happen in a four-to-six-week window from mid-August to late September, when colonies are at their biggest and workers have fewer larvae to feed and more time to forage for sugar. For more on the daily and seasonal activity cycle, see when are wasps most active.
When someone in Connecticut says they were “stung by a bee” at a cookout, it was usually a yellowjacket. Yellowjackets are social wasps in the genus Vespula. They’re smooth, shiny, and bright yellow and black, they fly fast and side to side, and a single wasp can sting more than once. Our Yellow Jackets hub guide covers their biology in depth.
This is the most common ground-nesting yellowjacket in Connecticut. Queens usually take over an abandoned chipmunk or vole burrow, and by late summer the colony can have several thousand workers in a paper nest the size of a basketball or bigger. The only sign above ground is usually a single entrance hole with steady traffic in and out. You’ll typically find it in lawns, under shrubs, in stone walls, or in the base of a railroad-tie garden bed.
Most Connecticut sting incidents follow the same pattern: someone mows over the hole, rakes the area, or steps near it, and dozens of workers come out at once. If you suspect a ground nest, see our guides to yellow jacket nests and wasps in grass.
The German yellowjacket is an introduced European species that’s now common in Connecticut, especially in towns and older neighborhoods. It looks almost the same as the eastern yellowjacket; the giveaway is a set of small black dots on the face and within the yellow bands of the abdomen. It differs in one way that matters a lot to homeowners: it often nests inside buildings, in wall voids, attic spaces, soffits, and sheds.
If you see yellowjackets going in and out of a gap in your siding, a vent, or a crack in the mortar, it’s probably this species. Don’t seal the hole while the nest is active. Blocked-in workers may chew through drywall and come out inside the house. See how are wasps getting in my house and the European wasp guide for more.
The aerial yellowjacket builds small gray paper nests, usually football-sized or smaller, in shrubs, low tree branches, and under eaves and porch roofs. Its colonies are smaller than those of the ground-nesting species and tend to finish earlier in the season. It’s defensive when the nest is disturbed, which usually happens while someone is trimming a hedge.
Connecticut has two very different insects that people call “hornets,” and neither is the “murder hornet.”
Despite its name, the bald-faced hornet is actually an aerial yellowjacket, not a true hornet. It’s black with ivory-white markings on the face and tip of the abdomen. It builds the classic large, gray, football-shaped (or bigger) paper nest in trees, shrubs, and sometimes under eaves or on the side of a house.
Bald-faced hornets defend their nest aggressively and will chase an intruder for a short distance. Many Connecticut homeowners first notice the nest in October, after it’s been hanging in a tree above their driveway all summer and the leaves fall away to reveal it. By then the colony is dying off, and after a couple of hard freezes the nest is empty and can be left alone or taken down. See the bald-faced hornet guide and bald-faced hornet sting.
The European hornet is the only true hornet established in Connecticut and the largest social wasp most residents will see, with workers over an inch long and queens up to about 1.4 inches. It’s brown, reddish, and yellow rather than black and yellow. It was introduced to the northeastern US in the 1800s and is now well established across southern New England.
Things Connecticut homeowners notice about European hornets:
Away from the nest, European hornets are fairly calm. Near the nest, they’ll defend it, and the sting is painful. See wasp vs hornet for more on how true hornets differ from other wasps.
No. The northern giant hornet (Vespa mandarinia), nicknamed the “murder hornet,” was only ever found in northwestern Washington State and British Columbia, and it was officially declared eradicated from the United States in 2024. It has never been found in Connecticut. Nearly every “murder hornet” report from Connecticut turns out to be a European hornet or a cicada killer.
If you find a hornet you truly can’t identify, the Connecticut Agricultural Experiment Station (CAES) and the UConn Home & Garden Education Center both help residents identify insects. More background is in our murder wasp guide.
Paper wasps (Polistes) are slender, long-legged wasps that let their legs hang down while they fly. They build a single open comb of paper cells, shaped like an upside-down umbrella, with no outer covering. Colonies are small, usually a few dozen wasps at most. They sting only when their nest is disturbed or when they’re pressed against skin. Our Paper Wasps hub guide covers them in detail.
This is the native paper wasp across Connecticut. It’s dark brown to reddish-brown with thin yellow bands and sometimes reddish markings. It nests under eaves, deck boards, porch ceilings, window shutters, and in sheds and outbuildings. It’s generally calm and a good caterpillar hunter in vegetable gardens.
The European paper wasp arrived in Massachusetts in the late 1970s and has since spread through all of New England. In many Connecticut neighborhoods it’s now the most common paper wasp around homes. It’s bright yellow and black, so people often mistake it for a yellowjacket, but it has the slim paper wasp body, dangling legs, and orange antennae. It likes small, protected spaces: hollow deck and fence railings, grill lids, mailboxes, outdoor light fixtures, and pipes. See the European paper wasp guide and paper wasp vs yellow jacket.
Mud daubers are solitary wasps. Each female builds her own nest and there’s no colony to defend. Connecticut has three common kinds:
Mud daubers stock their nests with paralyzed spiders (the blue mud dauber is known for taking black widows, along with many other species), and they almost never sting people. If a nest is in an inconvenient spot, you can scrape it off with a putty knife. See the mud dauber guide for identification and removal.
The biggest wasp many Connecticut residents ever see is the eastern cicada killer (Sphecius speciosus), which is 1.5 inches or longer with black and rusty-red bodies and pale yellow bands. They show up in July and August, when annual “dog-day” cicadas are buzzing, and dig burrows in sandy, well-drained soil: along walkways, in thin lawns, sand traps, playground sand, and baseball infields. Each burrow has a little U-shaped mound of loose soil at the entrance.
Males patrol the nesting area and dive-bomb people, but males can’t sting. Females can, but they rarely do unless you grab or step on one barefoot. See cicada killer wasps and cicada killer nest.
Other large, mostly harmless solitary wasps in Connecticut gardens include:
Plenty of Connecticut “wasp” problems turn out to be bees, and bees need different handling:
If you’re not sure what you’re looking at, see wasp vs bee and bee nest vs wasp nest.
Start with three questions: what species is it, where is the nest, and how late in the season is it?
Anyone with a known venom allergy, or anyone who’s had a serious reaction to a sting before, should not attempt nest removal. Keep prescribed epinephrine on hand during peak season and know the signs of an allergic reaction to a wasp sting.
For step-by-step methods, see the wasp nest removal safety guide.
For more, see how to keep wasps from building nests and what attracts wasps.
The most common are eastern and German yellowjackets, aerial yellowjackets, bald-faced hornets, European hornets, northern and European paper wasps, mud daubers, and cicada killers. Yellowjackets and bald-faced hornets cause most stings.
Queens start nests in April and May, colonies grow through June and July, and activity peaks from mid-August through September. The season ends after the first hard freezes, usually in October inland and late October to early November near the shoreline.
Colonies reach their largest size in late summer. At the same time, the colony stops raising workers and starts raising new queens and males, so workers spend more time foraging for sugar. That’s why yellow jackets show up at picnics, trash cans, orchards, and fall fairs this time of year.
Workers, males, and the old queen all die in fall. Only newly mated queens survive, overwintering alone in sheltered spots and starting new colonies in spring. Old nests aren’t reused. See where do wasps go in the winter.
Yes. The European hornet is a true hornet that’s established throughout Connecticut. The bald-faced hornet is also common, although it’s technically an aerial yellowjacket rather than a true hornet. There are no murder hornets (northern giant hornets) in Connecticut.
The eastern cicada killer, at 1.5 inches or more, is usually the largest, followed by European hornet queens at up to about 1.4 inches. Both are far less aggressive than their size suggests. See biggest wasp in the world.
Small, exposed paper wasp nests can usually be handled by a homeowner at night with proper precautions. Ground nests, nests inside walls, large hornet nests, and any nest you can’t reach safely from the ground should be handled by a licensed professional. If a nest isn’t in the way, waiting for frost is always an option.
Connecticut’s wasps follow a predictable pattern: quiet queens in spring, fast growth in summer, a busy late-summer peak, and a natural die-off in fall. Knowing which species you have is the key to deciding what to do. Yellowjackets in the ground or the walls are worth a careful, often professional, response. Paper wasps away from doorways, mud daubers, and cicada killers are usually best left alone.
This article is educational and does not replace professional pest control assessment or medical advice. Seek emergency care immediately for signs of a severe allergic reaction after any sting: difficulty breathing, swelling of the throat or tongue, dizziness, or widespread hives.
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.
Related guides: