Bald-Faced Hornet: Nest, Season and Sting Risk Explained

Quick answer

The bald-faced hornet (Dolichovespula maculata) is a black wasp with ivory-white face markings that builds a gray, football-shaped paper nest in trees, shrubs or under eaves, and despite its name is an aerial yellowjacket, not a true hornet.

Colonies grow to a few hundred workers by late summer. They help control flies and other insects, but defend the nest strongly.

Quick facts

The key facts about Bald-Faced Hornet, with sources:

Scientific name: Dolichovespula maculata, family Vespidae ¹
True hornet?: No; an aerial yellowjacket. The only true hornet in North America is the European hornet ¹
Size: Queens and workers 13–20 mm (about 1/2 to 3/4 inch) ¹
Colony size: 100–400 workers by late summer ¹
Nest: Gray paper, football-shaped; up to 24 in tall and 18 in across in Pennsylvania ¹
Nest height: Shrubs at least 3 ft up, trees to 60 ft or more, sometimes eaves ¹
Range: Most of the lower 48 states, Canada and Alaska ¹²

Key takeaways

The bald-faced hornet is named for the white markings on its black face, and it is really a type of yellowjacket.
Its gray, papery nest hangs in the open, often high in a tree, with one entrance near the bottom.
A colony lasts one summer and dies around the first hard frost; the empty nest is not reused.
Penn State says a nest can usually be left alone unless it is within 10 feet of a door, under a low eave or in shrubs beside a mowed lawn.
Spraying only the outside of a nest makes the colony angrier for days, which is why most people should hire a pro.

What a bald-faced hornet looks like and where it lives

Picture a wasp that is mostly black, with ivory-white marks on its face and more white on its thorax, legs and the tip of its abdomen ¹. That is the bald-faced hornet, about 1/2 to 3/4 inch long, and the queen is usually the largest wasp in the colony ¹.

It is not a true hornet, because scientists place it in the genus Dolichovespula, the “aerial yellowjackets.”

North America has 7 or 8 species in this group, and the bald-faced hornet is the most common one in Pennsylvania ¹.

The only true hornet on the continent is the European hornet, Vespa crabro, which arrived by accident ¹.

Bald-faced hornets live across most of the 48 contiguous states, throughout Canada and in Alaska ¹. UF/IFAS describes its range as most of North America ². You are most likely to notice it in late summer, when its nest is large and in full view.

Hornet in name only

Penn State calls the bald-faced hornet an aerial yellowjacket, not a true hornet ¹. The European hornet is larger, rust-and-yellow, and nests in hollow, sheltered spaces rather than in the open ³.

How a bald-faced hornet colony runs its season

Each colony lives only one summer, and the steps below follow the Penn State and UF/IFAS accounts.

Spring start: A queen that mated last fall comes out of her winter shelter. She gathers fiber from weathered or rotting wood, chews it into pulp and builds a few brood cells ¹.
First brood: Her first offspring become workers, who take over nest building, food gathering, feeding the larvae and guarding the nest ¹².
Summer hunting: Early in the season, workers catch live insects, including flies and even other yellowjackets, to feed the young ¹.
Growth: As the nest adds paper layers around the combs, the colony reaches 100 to 400 workers; large Pennsylvania colonies pass 300 ¹.
Diet switch: Later, with fewer larvae to feed, workers turn to nectar and other sugars ¹.
New queens and the end: In autumn the colony raises new queens and males. Most of the colony dies before or soon after the first hard frost, and only the new, mated queens survive the winter ¹².

Layers Inside a bald-faced hornet nest, outside to center

Paper envelopeGray layers of chewed wood pulp; entrance near the bottom ¹⁴
Air gapsSpace between envelope layers
Stacked combsSeveral tiers of open paper cells facing down
BroodEggs, larvae and pupae in the cells
AttachmentFixed to a branch, shrub or eave

A simplified diagram of the aerial yellowjacket nest form. UC IPM notes aerial nests usually have their entrance at the bottom. Source: [1] [4]

Our pest life cycle page shows how seasonal cycles like this shape control timing.

Bald-faced hornet and the insects called “hornets”

The word hornet is used loosely in the U.S. This table separates the insects behind it.
Insect	Group	Nest site	Colony size
Bald-faced hornet	Aerial yellowjacket, Dolichovespula ¹	Open, in trees, shrubs, eaves ¹	100–400 workers ¹
European hornet (Vespa crabro)	True hornet, introduced ¹³	Hollow trees, barns, attics, wall spaces ³	Up to about 400 workers, possibly 1,000 ³
Aerial yellowjacket (D. arenaria)	Aerial yellowjacket ⁴	Eaves, tree limbs ⁴	Not given in our sources
Ground yellowjackets (Vespula)	Yellowjacket ⁴	Underground, wall voids ⁴	1,500–15,000 by species ⁴

Example: deciding about a nest found in the yard

This illustration applies Penn State’s published distances and sizes to two nests. It is a way of thinking, not a rule for every yard.

Nest	Published guide	Reading
Nest 30 ft up an oak at the back of the lot	Trees up to 60 ft or more are normal sites ¹	Out of the way; leaving it is reasonable
Nest in a shrub beside a lawn you mow	Shrubbery next to a mowed lawn is a remove case ¹	Mower vibration can set off the colony
Nest under an eave by the back door	Within 10 ft of an entrance or under a low eave: remove ¹	People pass it daily; plan removal
Nest the size of a football in August	Pennsylvania nests reach 24 in tall, 18 in wide ¹	Near peak, with a few hundred defenders

In each case the deciding factor is distance from people, not the size of the nest alone. A big nest high in a tree is usually less of a risk than a small one by the door.

Where you will see bald-faced hornets

In the yard, look for a gray, papery ball the size of a football hanging from a branch, in a hedge or under an eave ¹.

Nests in shrubs are at least 3 feet off the ground, while tree nests can be 60 feet up or higher ¹. Many people only find them after leaves drop in fall.

On a service record, a technician may write “baldfaced hornet, aerial nest, front hedge.” Many companies group them with wasps and yellowjackets under stinging insects. Our stinging insect removal page explains a typical visit.

On a product label you will see the phrase “wasps and hornets.” The label is the legal limit on how a product can be used; see our pesticide safety page.

Warning signs of a bald-faced hornet nest

Black-and-white wasps flying in a steady line to one tree or shrub ¹.
A gray, football-shaped paper nest with an opening near the bottom ¹⁴.
Wasps hunting flies around a deck, barn or pet area in summer ¹.
Wasps visiting flowers and sweet foods in late summer, when they switch to sugar ¹.
A sudden swarm of defenders after a mower, trimmer or ladder bumps a hedge.

A disturbed nest can mean many stings

Hornets defend the nest as a group, and an injured wasp releases an alarm scent that triggers more defenders ². Vespid wasps can sting again and again ².

Hornet stings that bring trouble breathing or a swollen face or throat need a 911 call. People with known sting allergies should carry prescribed epinephrine ⁵ and have nearby nests removed by a professional ¹.

What bald-faced hornets do for your yard, and against it

Benefits

They hunt flies and other insects, including other yellowjackets ¹.
They pollinate flowers while feeding on nectar later in the season ¹.
The colony dies off around the first hard frost ¹.
A nest far from people can be left alone ¹.

Drawbacks

They defend the nest strongly and can sting repeatedly ².
Nests in hedges are easy to hit with trimmers and mowers ¹.
Spraying only the outside of a nest can raise stings for several days ¹.
Nests can be high and hard to reach safely ¹.

What makes hornet nests tricky to handle

Height is the biggest practical problem, because a nest 20 or 60 feet up a tree is hard to reach without a lift, and working on a ladder near angry wasps is a fall risk.

Partial treatment backfires too, and Penn State warns that spraying only the outside of a nest can anger the colony and increase stings for several days ¹.

Removing one nest does not prevent the next. Each spring, new queens pick fresh sites, and the yard that suited one queen may suit another. The old nest stays empty, and the Missouri Department of Conservation says the same of European hornet nests ³.

What drives the price of hornet nest removal

We do not list prices. A fair figure needs many dated quotes from your area. These are the factors that move a quote.

Height and access matter most, since a nest in a low shrub is a short job while a nest high in a tree or a second-story eave may need a lift or long pole, and some companies charge more for that.

Nest size and time of year matter too: a late-summer nest holds the most wasps.

Ask whether removal of the dead nest is included, and whether a return visit is free if wasps stay active. For homes with nests most years, a recurring plan may cover stinging insects; compare with the recurring plan tool and the cost guide.

How professionals usually deal with a bald-faced hornet nest

This explains what a company does so you know what to expect. It is not a guide to doing it yourself.

Confirm the insect and nest: The technician checks it is a hornet nest and not honey bees or a European hornet nest in a wall.
Plan access: Ladders, poles or lifts are chosen for the height, and people and pets are kept away.
Treat at night: Penn State describes treating at night with a labeled wasp and hornet product aimed into the nest opening, since the whole colony is inside ¹.
Protect the applicator: Long sleeves, long gloves and goggles are the minimum Penn State lists ¹; most pros use a full bee suit.
Wait and check: Activity should stop within a day or two.
Take the nest down: Once it is dead, the nest can be removed and bagged.

Do not knock it down or burn it

Hitting a nest with a stick, a hose or a ball releases hundreds of defenders. Burning a nest in a tree or under an eave is a fire hazard. Leave it alone or call a pro. For any pesticide exposure, call Poison Help at 1-800-222-1222.

No permit is needed for a home job, but companies that apply pesticides for pay must hold a state license. Learn more on our pest control licensing page.

Checks that reduce the chance of a hornet surprise

Walk the yard in early summer and look up into trees and under eaves, when nests are small.
Before trimming hedges or mowing beside shrubs in summer, watch for wasps flying in and out ¹.
Keep sweet foods and drinks covered outdoors in late summer, when workers switch to sugar ¹.
After leaves drop, take note of where old nests hung; queens may favor the same kind of spot.
In winter, an empty nest can be removed safely, because the colony is gone ¹.

See the seasonal pest calendar for when stinging insects peak near you.

When to bring in a pro

Call a professional if a nest is within 10 feet of a door, under a low eave or in shrubs next to a lawn, the three cases Penn State lists ¹.

Call if the nest is high up, if anyone at home is allergic to stings, or if wasps are entering a wall or attic.

Not sure if you see hornets, yellowjackets or bees? Then use the pest identifier first.

Rules for treating hornet nests

Federal (EPA, FIFRA): Every pesticide sold in the U.S. is registered by the EPA, under authority of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Penn State reminds readers to always read and follow the label and to store pesticides out of reach of children, pets and livestock ¹.

State: States license pest control businesses and their applicators. Check a company with the license lookup.

Not protected: Bald-faced hornets have no legal protection. Honey bees and some bumble bees are handled differently, so confirm the insect first.

Bald-faced hornet vs European hornet vs yellowjacket

Feature	Bald-faced hornet	European hornet	Ground yellowjacket
Color	Black with ivory-white marks ¹	Rust-brown, yellow and black ³	Black and bright yellow ⁴
Size	13–20 mm ¹	Workers up to 1 in; queens 1–1⅜ in ³	1/2 to 1 in ⁴
Nest	Exposed gray paper ball ¹	Hidden in hollow trees or buildings ³	Underground or wall void ⁴
Workers	100–400 ¹	Up to about 400, possibly 1,000 ³	1,500–15,000 ⁴
Nest reused?	No; colony dies at frost ¹	No ³	Colonies usually last one season ⁴

Chart Typical upper colony size, by insect

Upper colony sizes: paper wasp about 200 (UC IPM), bald-faced hornet 400 (Penn State), European hornet about 400 and possibly 1,000 (Missouri Department of Conservation), yellowjacket up to 15,000 depending on species (UC IPM).

Typical upper colony size, by insect (workers per colony)
Item	Value (workers per colony)
Paper waspUC IPM upper figure	200 workers
Bald-faced hornetPenn State upper figure	400 workers
European hornetMDC usual peak; possibly 1,000	400 workers
YellowjacketUC IPM upper figure, by species	15,000 workers

Data period: Extension and state agency figures, retrieved 2026-10-11

Source: [4] [1] [3]

Myths about bald-faced hornets

Myth It is a true hornet.: Reality It is an aerial yellowjacket; the only true hornet in North America is the European hornet ¹.
Myth A big nest means it will be back next year.: Reality The colony dies near the first hard frost and nests are not reused ¹³.
Myth Spraying the outside of the nest is enough.: Reality Penn State says this angers the colony and can raise stings for several days ¹.
Myth They are useless pests.: Reality They hunt flies and other insects and pollinate flowers ¹.

Range and climate notes

The bald-faced hornet lives across most of the 48 contiguous states, Canada and Alaska ¹, so the species is the same nearly everywhere.

What changes is the length of the season: colonies die around the first hard frost ¹, so in cold northern states the nest is empty by early fall, while in warmer southern states activity can run later.

Pennsylvania figures for nest size (24 inches tall, 18 inches across) come from Penn State and may differ elsewhere ¹.

Your decision, and what to do next

Measure distance first, because a nest high in a tree or at the back of the lot can stay until frost finishes it.

A nest within 10 feet of a door, under a low eave or in a hedge you trim should go ¹.

Any allergy at home moves it to the “call a pro” list.

From a safe distance, take a photo and note the height. That lets a company quote the job and bring the right equipment.

Decision guide

A nest high and far from people can stay. One within 10 feet of a door or in a hedge beside a mowed lawn calls for a licensed pro, and so does any sting allergy at home. An empty nest in winter is safe to take down.

Questions about Bald-Faced Hornet

Is a bald-faced hornet a real hornet?

No, the bald-faced hornet is not a true hornet. Penn State classes it as an aerial yellowjacket in the genus Dolichovespula.

The only true hornet in North America is the European hornet, Vespa crabro, which was brought over by accident.

The name stuck because of the large, exposed paper nest, which people think of as a hornet nest.

How many hornets are in a bald-faced hornet nest?

A bald-faced hornet nest usually holds 100 to 400 workers by late summer, according to Penn State, with large Pennsylvania colonies passing 300. That is far fewer than a ground yellowjacket colony, which can hold thousands. Even so, a few hundred defenders are enough to cause many stings if the nest is bumped.

Do bald-faced hornets reuse their nests?

No, bald-faced hornets do not reuse a nest. The colony dies before or shortly after the first hard frost, and only newly mated queens survive the winter. Each queen builds a brand-new nest in spring. An old nest you see in winter is empty and can be removed safely.

Are bald-faced hornets aggressive?

Bald-faced hornets are defensive near their nest but rarely bother people away from it.

If the nest is bumped, many workers come out at once, and an injured wasp gives off an alarm scent that draws more defenders, per UF/IFAS.

Away from the nest, a single hornet hunting flies or drinking nectar is unlikely to sting unless handled.

Where do bald-faced hornets build nests?

Bald-faced hornets build gray, football-shaped paper nests in the open. Penn State lists shrubs at least 3 feet off the ground, trees up to 60 feet or higher, and sometimes building eaves, and each nest has an entrance near the bottom.

Many nests go unnoticed until fall, when leaves drop and the nest is easy to see.

Should I remove a bald-faced hornet nest?

Remove it only if it is close to people, since Penn State says nests can usually be left alone unless they are within 10 feet of a building entrance, under a low eave, or in shrubs next to a mowed lawn.

People with sting allergies should have nearby nests removed by a professional. A nest high in a tree is often best left for the frost to end.

What is the difference between a bald-faced hornet and a European hornet?

They differ in color, size and nest site: the bald-faced hornet is black with white face markings and builds an exposed nest in trees or shrubs.

The European hornet is larger, with rust-brown, yellow and black coloring, and nests in hollow trees, barns, attics or wall spaces. Missouri’s conservation department notes European hornets are sometimes drawn to lights at night.

Are bald-faced hornets beneficial?

Yes, bald-faced hornets do useful work, and Penn State says workers hunt flies and other insects, including other yellowjackets, and help pollinate flowers while feeding on nectar later in the season. That is the reason experts suggest leaving nests that are well away from homes and paths.

What should I do if a bald-faced hornet stings me?

Move away from the nest first, then wash the sting with soap and water and apply ice, as CDC NIOSH advises. Ask another person to stay nearby and watch for an allergic reaction.

Call 911 right away for trouble breathing, swelling of the lips or throat, or fainting. If you carry prescribed epinephrine for a known allergy, use it and get emergency care.

Sources

Penn State Extension, Baldfaced Hornet, retrieved October 11, 2026.
University of Florida IFAS, Yellowjackets and Hornets (EDIS IN238), retrieved October 11, 2026.
Missouri Department of Conservation, Field Guide: European Hornet, retrieved October 11, 2026.
UC Statewide IPM Program, Pest Notes: Yellowjackets and Other Social Wasps (Publication 7450), retrieved October 11, 2026.
CDC NIOSH, Insects and Scorpions at Work, retrieved October 11, 2026.

Expert review

Written by the HyrePest Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.

How the numbers were checked: Classification, size, range, nest, colony, season and management-distance facts follow Penn State Extension. Range, alarm pheromone and repeated-sting facts follow UF/IFAS EDIS IN238.

European hornet facts follow the Missouri Department of Conservation. Yellowjacket and paper wasp comparison figures follow UC IPM. Sting first aid follows CDC NIOSH. No prices or application rates are given.

Suggest a correction. We fix errors and say what changed.