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Bald-faced Hornet

Dolichovespula maculata[4][2]

The bald-faced hornet is a large black-and-white aerial yellowjacket that builds gray, football-shaped paper nests in trees, shrubs and on buildings and defends them aggressively.[1][2][5][6]

Group
Insect
Order
Hymenoptera
Family
Vespidae
US records
41 states
Sources
12 cited
Updated
2026-11-11
Bald-faced hornet, black with white markings on the face and body
Bald-faced hornet, black with white markings on the face and body. (c) Amy Schnebelin, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0
On this page
  1. Identification
  2. Look-alikes
  3. Where it lives
  4. Biology
  5. Damage and signs
  6. Health risk
  7. Control
  8. Related profiles
  9. Common questions
  10. Sources

How to identify it

  • Larger than yellowjackets and black with white rather than yellow markings.[1][2][5][6]
  • Look for the white or ivory face that gives it its name. MDC adds white markings on the thorax and near the tip of the abdomen and dark brown, see-through wings; Clemson counts three white stripes at the end of the body.[6][5]
  • Size estimates differ a little: Clemson says workers average about 3/4 inch, with queens only slightly larger, while MDC gives 1/2 to 3/4 inch for workers and 3/4 inch for queens.[5][6]
  • Nests are large, gray and shaped like a bloated football, with a single opening usually near the bottom, often hidden among branches.[1][2][5]
  • Clemson says nests are often pear- or egg-shaped and can reach 14 inches across and more than 23 inches long, with a mottled gray paper envelope around several layers of comb.[5][6]

Look-alikes

Look-alikeHow to tell them apart
YellowjacketSmaller, black and yellow, and usually nests in the ground or in wall voids.[2][1][7]
European hornetSimilar in size and often mistaken for it, but Clemson says the European hornet is the only true hornet in North America, and MDC says it builds its nest in dark hollows such as hollow tree trunks, not underground.[5][7]

Where it lives

Nests hang from tree limbs and shrubs or attach to eaves and the sides of buildings.[2][1]

US map: public records from 41 states since 1990 (GBIF).

Biology and life cycle

Colonies hold hundreds of wasps and die off when cold weather arrives; the paper nest breaks down over winter.[1][3][6]

Colony sizes vary by source: Clemson says colonies average about 400 workers, ranging from 100 to 700, and MDC says late-summer nests may hold several hundred.[5][6]

Clemson says queens come out of stumps, logs and loose bark from April to June, and new queens and males appear from early July to September. MDC puts the new queens and males later, as winter begins.[5][6]

Unlike ground-nesting yellowjackets, aerial nesters don't become scavengers at the end of the season.[2][6]

Adults mostly drink nectar, while the larvae are fed chewed-up insects and spiders.[6][5]

Clemson says reused nests have only been seen in more tropical parts of North America.[5]

Damage and signs

  • Bald-faced hornets eat other insects, including yellowjackets, but their nests near people are a stinging hazard.[2][1][5]
  • Nests in trees and shrubs often go unnoticed until the leaves drop in fall, and MDC says many are so high off the ground they pose little problem.[5][6]
  • Bald-faced hornets are extremely defensive near the nest and can sting repeatedly. Clemson adds that they can squirt venom from the stinger toward the eyes of a nest intruder.[2][1][5]
  • Researchers found that venom-sac extract placed near nests made the hornets strike 27 times more often, evidence of an alarm pheromone that rallies nestmates to attack. UK says this kind of pheromone is what turns one disturbance into a coordinated assault.[8][1]

Health risk

Stings usually bring pain and swelling at the site. A person allergic to the venom can develop anaphylaxis, which MedlinePlus says can occur very quickly and lead to rapid death if not treated; a 2018 review of US data found hornets, wasps and bees caused 29.7 percent of animal-related deaths from 2008 to 2015.[11][10][9]

Control

Prevention

If the nest is away from where people go, consider waiting: colonies die naturally once the weather turns cold.[1][5]

Traps and physical control

Clemson says the light should point at the nest but not be held by the person treating it. Penn State says eye protection helps because some yellowjackets can spray venom at the eyes.[5][12]

Pesticides

Anyone who treats a nest themselves should do it at night in a full wasp suit and veil sealed at the wrists, ankles and collar. UK advises spraying a wasp and hornet aerosol or puffing dust into the single opening near the bottom without breaking the paper envelope, then waiting at least 3 to 4 days before taking the nest down.[1]

Clemson notes that foaming wasp sprays expand inside the nest, while dusts can take several hours to work and require getting close.[5]

When to call a professional

Nests are often high and hard to reach, and breaking the paper envelope scatters angry hornets; hiring a professional is usually best.[1][5]

Common questions

Will the nest be used again next year?
No. Colonies die off in winter and the paper nest disintegrates; queens start new nests in spring.[1][2][5][6]
What should I do if hornets come after me?
If several attack at once, run to get away from them; NIOSH says a shaded area is better than an open one, and don't jump into water, because some insects hover above it. Don't swat at a single wasp flying around you, as that can provoke a sting.[10]

Sources

  1. University of Kentucky Entomology, “ENTFACT-620: Controlling Wasps, Hornets, and Yellowjackets.” entomology.mgcafe.uky.edu/ef620 (accessed 2026-11-11)
  2. University of California Statewide IPM Program, “Pest Notes: Yellowjackets and Other Social Wasps, Publication 7450 (March 2012).” ipm.ucanr.edu/legacy_assets/PDF/PESTNOTES/pnyellowjackets.pdf (accessed 2026-11-11)
  3. University of Kentucky Entomology, “ENTFACT-411: Yard Wasps.” entomology.mgcafe.uky.edu/ef411 (accessed 2026-11-11)
  4. iNaturalist, “Dolichovespula maculata taxon page (order and family).” www.inaturalist.org/taxa/52911 (accessed 2026-11-11)
  5. Clemson Cooperative Extension Home & Garden Information Center, “Baldfaced Hornets.” hgic.clemson.edu/factsheet/baldfaced-hornets/ (accessed 2026-11-11)
  6. Missouri Department of Conservation, “Bald-Faced Hornet, Field Guide.” mdc.mo.gov/discover-nature/field-guide/bald-faced-hornet (accessed 2026-11-11)
  7. Missouri Department of Conservation, “Yellowjackets (Vespula Wasps), Field Guide.” mdc.mo.gov/discover-nature/field-guide/yellowjackets-vespula-wasps (accessed 2026-11-11)
  8. Journal of Chemical Ecology, via PubMed, “Jimenez SI et al. (2016), Evidence for a Nest Defense Pheromone in Bald-Faced Hornets, Dolichovespula maculata, and Identification of Components, Journal of Chemical Ecology 42(5):414-424.” pubmed.ncbi.nlm.nih.gov/27146994/ (accessed 2026-11-11). Cited from the PubMed abstract.
  9. Wilderness & Environmental Medicine, via PubMed, “Forrester JA, Weiser TG, Forrester JD (2018), An Update on Fatalities Due to Venomous and Nonvenomous Animals in the United States (2008-2015), Wilderness & Environmental Medicine 29(1):36-44.” pubmed.ncbi.nlm.nih.gov/29373216/ (accessed 2026-11-11). Cited from the PubMed abstract.
  10. Centers for Disease Control and Prevention, NIOSH, “Insects and Scorpions at Work.” www.cdc.gov/niosh/outdoor-workers/about/insects-and-scorpions.html (accessed 2026-11-11)
  11. MedlinePlus, U.S. National Library of Medicine, “Insect bites and stings (Medical Encyclopedia 000033).” medlineplus.gov/ency/article/000033.htm (accessed 2026-11-11)
  12. Penn State Extension, “Getting Rid of Paper Wasps, Yellowjackets, and Other Stinging Insects.” extension.psu.edu/getting-rid-of-paper-wasps-yellowjackets-and-other-stinging-insects (accessed 2026-11-11)

Updated 2026-11-11. Built from sourced records. Spot an error? Tell us.