Reviewed by William "Willy" Vizcarrondo, NYS Certified Pesticide Applicator (C1825832). Updated September 23, 2026.
Yellowjackets and bald-faced hornets are the social wasps that make late summer on Long Island dangerous around decks, garbage cans, and anywhere kids play. A colony that started with one queen in April can hold 5,000 workers or more by the end of August, and they defend the nest as a group.
| Size | Yellowjackets about 1/2 inch; bald-faced hornets 5/8 to 3/4 inch |
|---|---|
| Color | Yellowjackets black with bright yellow bands; bald-faced hornets black with white face and markings |
| Look-alikes | Paper wasps (longer legs, slimmer, open umbrella nests under eaves), honey bees (fuzzy, golden brown), cicada killers (much larger, solitary) |
| Where you'll find it | Yellowjackets in the ground, wall voids, soffits, under decks and sheds; bald-faced hornets in gray paper nests in trees and on eaves |
| Active on Long Island | April through first hard frost; danger peaks August through September |
| Danger level | Painful stings, group defense, severe allergic reactions |
Queens start nests in April, colonies grow all summer, and by August and September on Long Island the nests are at full strength and the workers are aggressive around food.
Yellowjackets are smooth, not fuzzy, about half an inch long, black with sharp yellow bands, and they fly fast and straight. Bald-faced hornets are bigger, black with a white face, and their nests are the gray paper footballs hanging in trees and from eaves.
Paper wasps are slimmer with long dangling legs and build small open-comb nests you can see the cells of. If it's fuzzy and golden it's a honey bee, and that's a call to a beekeeper, not an exterminator (Cornell IPM).
Yellowjackets deliver painful stings, and a crushed or threatened worker releases an alarm pheromone that brings the rest of the colony out (Cornell IPM). Ground nests under a lawn and nests in wall voids are the ones that hurt people, because you find them by stepping on them or by mowing over them.
For anyone with a sting allergy, a nest near the house is a medical risk, not a nuisance.
A brand-new nest in spring with a handful of workers, sometimes. An established nest in August, no. Cornell IPM's advice is to destroy young nests early and leave established colonies to professionals, because pesticide sprays agitate yellowjackets and make them more dangerous.
Wall-void nests are the worst DIY case: sealing the hole from outside sends thousands of wasps into the house.
We locate the nest, treat it directly with the right product for a ground nest, wall void, or aerial nest, and remove aerial nests once the colony is dead. Wasp and hornet treatment carries a 6-month written guarantee.
Related answers
Yes. Only the mated queens survive winter, and they start new nests from scratch in spring. The old nest is not reused, but a wall void that held one nest is attractive to a new queen the next year if it isn't sealed.
Usually a nest in a wall void or attic. Workers follow light and end up at a window or ceiling fixture. Don't seal the outside hole; that pushes the colony indoors.
On Long Island the "hornet" you see is the bald-faced hornet, which is a large black and white yellowjacket that builds a gray paper nest in the open. Regular yellowjackets are smaller, yellow and black, and nest in the ground and in structures.
No. Vibration and the mower passing over the hole trigger a group attack. Mark the spot, keep people and pets away, and have it treated first.
Think you have yellowjackets or hornets? Call (516) 509-6001 for a free written quote.