The most defensive social wasp most Americans will meet. It guards a large nest aggressively, stings repeatedly, and can spray venom towards the eyes of something at the nest. Away from the nest it is unremarkable.
We identify, we don't diagnose. If you've been bitten or stung and symptoms develop, or you're worried, seek medical attention.
Size18–20 mm; queens larger
MarkingsBlack with an ivory-white face — the only common wasp with a white face · White markings at the tip of the abdomen, not banded yellow
WhereNests hung from tree branches, shrubs, eaves and wall faces, usually well off the ground.
SeasonNest grows through summer, at maximum late summer, abandoned in winter
How to tell it apart
Black with an ivory-white face — the only common wasp with a white face
White markings at the tip of the abdomen, not banded yellow
18–20 mm, stocky, hairless and glossy
Nest is a large grey paper envelope, football-sized, hanging in a tree or on a wall
Guards visible at the single entrance hole near the bottom of the nest
Where you’ll find it
Across most of the United States and southern Canada.
Nests hung from tree branches, shrubs, eaves and wall faces, usually well off the ground.
Nest grows through summer, at maximum late summer, abandoned in winter.
How it behaves
Despite the name it is not a true hornet but a large relative of the yellowjacket, and it behaves like one with a bigger nest and a shorter temper. A mature colony can hold several hundred workers behind a paper envelope, with guards at the entrance. Defence starts at a longer range than most wasps — several metres — and unusually they will aim venom at the face of a persistent intruder, which is genuinely painful in the eyes. They also hunt yellowjackets, which is a point in their favour.
What a bite looks like
A red weal with pronounced local swelling, sometimes for several days.
Sharp, hot pain. Multiple stings are common in an encounter because the colony responds together and each wasp can sting more than once.
We identify, we don't diagnose. Seek medical attention immediately for venom in the eyes, for breathing difficulty, facial or throat swelling, or faintness — and for multiple stings, which are more likely with this species than with any other here.
A skin mark cannot confirm which animal caused it. Read the bug bite and sting guide for the limits and the symptoms that should end an online search.
You’ve found one indoors
Keep your distance and do not throw anything at the nest. A nest high in a tree away from paths can usually be left; it is abandoned by winter and never reused. A nest near a door, a play area or a work area is a professional job, not a dusk-and-a-spray-can job — this is the species most likely to produce a multiple-sting incident.
Common questions
Is a bald-faced hornet a real hornet?
No. It is a large yellowjacket relative. The distinction matters little for how to behave around it and quite a lot for identifying it — no true hornet in the US has a white face.
Can it really spray venom?
Yes, at the eyes of something at the nest. It is not a long-range attack and it is a real reason not to stand and stare at a nest.
How close is too close?
Several metres, which is further than most people expect. If guards come out to face you, you are already close enough.
Will they use the nest again next year?
No. The colony dies in winter and a new queen builds elsewhere. An empty winter nest is harmless and can be removed at leisure.
Zachary Dankowicz · CC-BY