STINGING INSECT GUIDE

Baldfaced hornet

Identification, local timing in San Antonio and the Hill Country, risk profile, and exactly how we treat it.

Scientific name: Dolichovespula maculata (Linnaeus, 1763) Common names: Baldfaced hornet, bald-faced hornet, white-faced hornet, bald-faced aerial yellowjacket, bald hornet, spruce wasp, bull wasp, blackjacket, white-tailed hornet. Family: Vespidae (subfamily Vespinae). Status in the San Antonio / Boerne corridor: Native and present, but not abundant. It’s the only "hornet" you’re likely to see around here.

At a glance #

Identification #

You can't really mix up a baldfaced hornet with any other insect.

• Color pattern: These guys are bold with their black-and-white look. Forget yellow and black. The white face, often called "bald face," is easy to spot. You'll also see white markings on their thorax and the last three segments of the abdomen. All other local wasps have yellow markings; baldfaced hornets stand out with their white.
• Size: They're large — about 3/4 inch long, which makes them noticeably bigger than yellowjackets. They’re roughly the size of a paper wasp but stockier and more robust.
• The nest: This is the most reliable way to identify them. If you see a large, gray, football-shaped paper nest hanging from a tree branch, it’s definitely a baldfaced hornet nest. No other common wasp in North America builds nests like that.

"Bald" in the common name doesn't mean hairless. It actually comes from an older English term that means "having a white spot," related to piebald. The white face marking is what makes it "bald." Carl Linnaeus first described this species in his 1763 work, Centuria Insectorum.

Not actually a hornet #

Baldfaced hornets aren’t actually hornets. This is important because it changes how we classify, understand, and deal with them.

True hornets belong to the genus Vespa. This includes the European hornet and the infamous Asian giant hornet, often called the "murder hornet." There are also several other Vespa species from Asia and Europe. On the other hand, baldfaced hornets are classified under Dolichovespula, which is actually a type of aerial yellowjacket. They’re more closely related to yellowjackets than to true hornets, despite the name.

The term "baldfaced hornet" might sound intimidating, but it's a bit misleading. These insects are actually large yellowjackets, not true hornets. According to Texas A&M AgriLife Extension, "It actually belongs to the yellowjacket family (Vespidae)." It's the only species called a hornet that's found in Texas, so don’t be fooled by the name.

Biology and behavior #

Annual cycle #

Like most temperate-zone social wasps, baldfaced hornet colonies are annual. The cycle:

• Spring (April–May in Central Texas): A mated queen that survived the winter in a safe spot comes out and starts building a small nest. She lays eggs, raises the first batch of workers on her own, and starts forming the initial paper envelope.
• Summer: The first workers show up, usually about 19–23 days after the eggs are laid. They take over expanding the nest, foraging for food, and taking care of the larvae. Meanwhile, the queen focuses on laying more eggs. The colony grows quickly.
• Late summer / fall: The colony hits its peak with around 100–700 workers — that’s the biggest size for any Dolichovespula species. The nest can grow up to 14 inches wide and 23 inches long.
• Fall: The colony starts producing males and new queens. The males mate and then die shortly after, while the new queens look for places to hibernate.
• First freeze: The old queen, males, and all workers die off, leaving the nest empty and abandoned.

Baldfaced hornets do not reuse their nests. If you spot a 23-inch paper football in your oak tree in February, it’s just an empty shell. The colony inside died off months ago, and the queens that will start new colonies next year are hibernating somewhere else entirely.

The nest — a genuine engineering feat #

The baldfaced hornet nest is one of the more remarkable structures any insect builds in North America:

• Construction material: These nests are made from weathered wood fibers scraped from old boards, bark, and fences, mixed with saliva to create a pulp. It’s pretty much hand-made paper.
• Structure: You’ll find multiple horizontal combs of hexagonal cells stacked inside a paper envelope that can be spherical to elongated. There’s just one small entrance at the bottom.
• Size: Nests can grow to 14 inches in diameter and 23 inches in length — about the size of a basketball to a football.
• Color banding: The paper envelope often shows visible gray banding from different wood sources collected over time. If you look closely at a mature nest, you can see its layered construction history.
• Height: These nests can be found anywhere from 1 foot to 65 feet off the ground. Most residential nests are typically 15–30 feet up in mature tree canopies.

The interior of a wasp nest has multiple horizontal layers of comb. You'll find larvae hanging head-down in each cell. The outer envelope keeps the nest safe from bad weather, helps regulate temperature, and offers protection from most predators.

The "matricide" phenomenon #

Here's a strange fact about baldfaced hornets that even experts find intriguing. In studies of mature colonies during their reproductive phase, researchers looked at 19 nests and discovered that 14 nests had no queen. It's possible that the workers killed their own queen, or she could have died naturally just as the colony began to reproduce. While we haven't directly observed this matricide, the number of queenless nests during this phase is significant enough to suggest that workers might be the ones doing the killing.

The reason behind this behavior is mostly evolutionary. When a colony has enough worker bees and the queen has laid her eggs, her presence can actually hinder the colony's reproductive plans. Female workers can lay haploid eggs that turn into males. If the queen is gone, they can start contributing to the colony's reproduction. Eliminating the queen at the right time allows the workers to pass on their own genes.

Dolichovespula is different from its yellowjacket (Vespula) relatives because some of its workers can produce haploid offspring that turn into males. This is something you typically won't see with Vespula workers.

The diet #

Adults feed on nectar, tree sap, fruit pulp (especially apples), and honeydew from aphids. I've seen them scavenge for raw meat, carrion, and other insects too. They’re not picky eaters.

Larvae need protein to grow. Worker wasps hunt down live insects like flies, caterpillars, spiders, and even other wasps. They chew these into a paste and feed it to the larvae. In exchange, the larvae secrete a sugary saliva that the adult workers eat. This creates a cycle that keeps the colony's food supply running smoothly.

Baldfaced hornets are tough predators of pest insects. A mature colony can take out thousands of caterpillars, flies, and aphids during the summer. North Carolina State University Extension even says this species is "probably beneficial because they prey on plant pests."

Venom spraying — a real thing #

Baldfaced hornets can spray venom from their stingers. I've seen this behavior in action. When they feel threatened near their nest, they can aim and squirt venom a short distance—enough to hit an intruder's eyes. The venom burns intensely and can even cause temporary vision loss. Most of the time, they stick to regular stinging for defense, but this venom-spraying is real. That’s why we always wear eye protection when dealing with an active nest.

Local context — San Antonio and the Hill Country #

Baldfaced hornets are around, but not in huge numbers, in the San Antonio to Boerne area. They prefer forest edges, so the less wooded spots—like central Bexar County and the drier western areas—tend to generate fewer calls compared to the communities with plenty of oak trees.

Where we see baldfaced hornet nests locally:

• Fair Oaks Ranch mature live oak canopy — classic habitat. Every summer, homes with large mature oaks often have a baldfaced hornet nest tucked away in the canopy. Most of these nests are 20–30 feet up and pretty much unreachable.
• Bulverde and Spring Branch acreage properties — more wooded, more nests. Pecan and live oak stands are where most of the nests pop up.
• Canyon Lake wooded lots — these areas have shoreline oaks and cedar-juniper stands that can house nests.
• Boerne ISD school campuses with mature trees — we see recurring service calls from these locations.
• Urban San Antonio mature tree neighborhoods — Alamo Heights, Terrell Hills, Monte Vista, Olmos Park, Mahncke Park. Downtown San Antonio's tree canopy produces a few nests every season.
• Less common: on buildings. Baldfaced hornets will sometimes build on eaves or the sides of structures, but they prefer trees when they can find them.

The "when to remove" judgment call #

Not every baldfaced hornet nest requires removal. The genuine risk calculation:

• Nest within 10 feet of human activity: Remove. The risk of stings is real, and they defend their nest aggressively within about 10 feet.
• Nest 15–25 feet up in a canopy tree with no regular human activity below: Usually leave alone. I mark the tree on a map, advise the homeowner to steer clear, and wait for frost. The colony dies off in November, so the issue resolves itself.
• Nest on a building eave, patio, or outdoor living structure: Remove. Their close proximity to where people hang out means conflict is likely.
• Nest in a tree adjacent to a pool, playset, or driveway: It's a judgment call based on the specific layout. Often, I recommend removal just to be safe.

Every year, we get calls from clients wanting to remove nests that are 40 feet up in a secluded corner of their 10-acre lot. We’ll do the job if that’s what they want, but I usually recommend waiting until winter. Taking down an abandoned nest in the dead of winter is a lot easier than dealing with a live colony at that height.

Risk to humans and pets #

Moderate to high risk is present within the defensive radius of the nest. Outside of that area, the risk is low.

A baldfaced hornet searching for flowers or munching on fallen fruit isn’t likely to bother you — she’ll just go about her business. But if she feels you’re a threat to her nest, that’s a different story. This species gets aggressive, stings multiple times, and can even spray venom into your eyes.

Sting pain from these insects is rated at 2.0 on the Schmidt Pain Index. That’s comparable to yellowjackets but less painful than a red wasp. Justin Schmidt described the sting as "rich, hearty, slightly crunchy," which is a pretty vivid way to put it. According to Wikipedia, it feels kind of like getting your hand caught in a revolving door. The real danger isn’t just from one sting; it’s when they attack in groups to defend their nest. That’s when you might face mass envenomation, especially since they can spray venom at your eyes too.

Treatment approach #

• Daytime reconnaissance, nighttime treatment. Aerial nests are best treated at dusk or dawn when the workers are inside.
• Extension equipment for canopy nests. Most residential nests sit 15–30 feet up. We use professional pole-applied aerosols to reach this height; consumer products just can't do it.
• Protective equipment: You need a bee suit, a sealed veil, and eye protection. The risk of venom spray is real.
• Treatment protocol: We apply a pyrethrin-based aerosol to the nest entrance and exterior. When workers return, they contact the treated surface and die. We keep treating over 24–48 hours until there's no more activity.
• Nest removal: Once activity stops, we cut down the nest and dispose of it. Leaving a nest might not matter since they're abandoned every year, but most homeowners prefer to have it gone.
• Very high nests (30+ feet): We monitor until frost. Full aerial removal is possible with specialized equipment but can get pricey; if a nest is high enough to be out of reach, waiting for winter is a valid option.

Odd, funny, and genuinely true #

• Songbirds use baldfaced hornet nest paper. Chickadees, nuthatches, and several warbler species have been documented pulling paper fragments from abandoned nests to use as nesting material for their own broods. An old winter nest is effectively a free construction material depot for the following spring's birds.
• The pheromone chemistry of baldfaced hornet nest defense has been chemically analyzed. Research published in 2016 by Jimenez et al. identified specific pheromone compounds that baldfaced hornets release during nest defense, triggering more workers to join the attack. The chemistry of the alarm pheromone has a kind of "maculatic acid" signature that is specific to D. maculata.
• A male baldfaced hornet sex attractant pheromone was identified in 2018 — "Maculatic Acids" — and published in Angewandte Chemie, a leading chemistry journal. The fact that chemists are isolating and naming pheromones after this species gives you a sense of how well-studied it is.
• Bee moths parasitize baldfaced hornet nests. The female bee moth (Aphomia sociella) — not actually a bee, just similar in appearance — lays her eggs inside active Dolichovespula nests. The moth larvae eat the hornet eggs, larvae, and pupae. Entire hornet colonies can be destroyed from the inside by this parasite.
• Baldfaced hornets have been captured alive in New Zealand — they are not native there, but individual specimens have been collected in Dunedin, suggesting possible accidental introduction events. No established population has ever been documented outside North America.
• A baldfaced hornet nest has three "zones" you can identify at close range. The outer envelope, the inner suspension points where combs hang from the envelope, and the individual comb tiers with cells. You can see all three structures by looking up at an abandoned winter nest with a flashlight — the paper is translucent enough to see interior shadows.
• The "piebald" origin of the name "bald-faced" is a fascinating linguistic fossil. In older English, "bald" simply meant "white-marked" or "having a white spot." A "bald eagle" has a white head; a "baldfaced hornet" has a white face. The meaning drifted toward "hairless" in other contexts but the original sense survives in a handful of specific names.
• The longest recorded baldfaced hornet nest was 58 cm (23 inches) long. That's close to two feet — hanging from a single tree branch, built from paper made by wasps chewing wood fiber all summer. The weight of a nest of that size plus all workers is nontrivial.
• Workers recognize their own nest by cuticular hydrocarbons — surface chemicals on the exoskeleton that function like colony-specific perfume. A baldfaced hornet from one colony can immediately distinguish nestmates from intruders. Research in 1985 by Ryan, Cornell, and Gamboa established this nestmate-recognition system in D. maculata.
• The "bald-faced" marking gets more prominent as the wasp ages. Freshly emerged workers have a less contrasty face pattern than older wasps. This is because the cuticle darkens over the first few days after emergence, making the white areas appear whiter against a darker background. It's why old worker photos show the classic striking face pattern and fresh-emergence photos look slightly washed out.

Common questions customers ask #

• Got a big gray wasp nest in my tree — what is it?
• Are baldfaced hornets actually real hornets?
• How do you get rid of a hornet nest from a tree?
• Are baldfaced hornets something to worry about?
• What's the difference between a hornet and a yellowjacket?
• Will baldfaced hornets return to the same nest next season?
• Do baldfaced hornets pack a sting?
• Can baldfaced hornets spray venom like a skunk?

We pulled information from a variety of sources for this guide. These include the original description by Linnaeus from 1763 (Centuria Insectorum), NC State University Extension on baldfaced hornets, LSU AgCenter species account, and Texas A&M AgriLife Extension's Field Guide to Common Texas Insects. I've also looked at peer-reviewed research regarding nestmate recognition (Ryan et al. 1985), studies on cuticular hydrocarbons (Butts et al. 1991), and the Maculatic Acids paper (Ren et al. 2018, Angewandte Chemie). The Schmidt Sting Pain Index (Schmidt, The Sting of the Wild, 2016) also helped. For colony sizes, I referred to Akre et al. 1981 from the USDA Yellowjackets of North America handbook.

Frequently asked questions #

How can I identify a baldfaced hornet? #

Baldfaced hornets are large, with a black body and distinctive white markings on their face and thorax. They typically measure about 0.5 to 0.75 inches long. If you see a nest, it will be a gray, paper-like structure, often found in trees or shrubs.

What behavior should I expect from baldfaced hornets? #

These hornets are quite aggressive, especially when defending their nests. They can sting multiple times, which makes them a risk if you accidentally disturb their nest. It's best to keep your distance and avoid provoking them.

When is baldfaced hornet season in San Antonio? #

In San Antonio and the Texas Hill Country, baldfaced hornets are most active from late spring through early fall. You'll often see them building nests in late spring, and their activity peaks during the summer months.

What should I do if I find a baldfaced hornet nest on my property? #

It's best to leave the nest alone and contact a pest control professional like us. We have the experience and tools to safely remove the nest without increasing the risk of stings. Trying to handle it yourself can lead to aggressive behavior from the hornets.

How much does it cost to treat a baldfaced hornet problem in my yard? #

The cost can vary depending on the size of the infestation and the location of the nest. After assessing the situation, we can provide a clear estimate. Generally, treatment is most effective when scheduled during their active season.

Last reviewed April 25, 2026 by Travis Lambert (Owner).