How to Identify a Hornet

Hornets, a species belonging to the Vespa genus, are the largest and most aggressive members of the wasp family (Vespidae), with some species reaching sizes of up to 5.5 cm. However, European hornets are less aggressive and rarely sting unless provoked or their nests are threatened. Many insects are often mistaken for hornets, but there are only 20 true hornet species worldwide. These insects are classified as hornets not only because of their aggression but also due to the venom of certain species, which can cause excruciating pain or even death, as seen with the Giant Asian Hornet. The best way to avoid stings is to identify hornets by recognizing their nests or the hornets themselves based on their distinctive features.

Look for an oval-shaped, gray object resembling paper. Although it’s not actually paper, it is a substance that resembles paper made from hornet saliva and wood fibers. The nest is where eggs are nurtured, and hornets are highly protective of both their nest and eggs. You definitely don't want to be caught near a hornet's nest, as they might see you as a threat.

• Initially, the nest appears as a small, honeycomb-like structure, but it gradually grows and expands into an oval shape resembling a football, stalactites, or an upside-down water drop.
• This means that identifying the nest structure will help narrow down the possibilities of identifying the insect species near your home, even if you can't precisely determine which insect it is yet.
• Paper wasps also build nests from materials similar to paper, but their nests don’t have the protective paper-like outer shell surrounding the nest.

Look for hornet nests outdoors, elevated and sheltered. Hornets tend to build their nests in outdoor areas, often high off the ground, such as on trees, utility poles, or in dense shrubbery. They may also create nests beneath overhanging roofs or under the floorboards of porches.

• Typically, hornet nests are hidden from view until autumn, when fallen leaves reveal their location. By this time, most of the hornets will have perished, with only the queen surviving to hibernate through the winter.
• In contrast, yellowjackets often build their nests near the ground, underground, or in any cracks or gaps they can find, such as between walls, inside a house, or even within an old mattress.
• Some wasps that build high nests are commonly mistaken for hornets. The bald-faced hornet from North America is actually a type of wasp, as is the Australian hornet, which is a subspecies of the mason wasp.

Estimate the number of hornets in the nest. A hornet nest can accommodate up to 700 hornets. If you encounter a larger nest that seems to house thousands of hornets, it’s likely a yellowjacket nest. Therefore, careful observation from a distance is key in determining whether you’re dealing with hornets or yellowjackets.

• Regardless of the nest size, the best approach is to call a professional. They will need to know the nest’s size, so the more details you provide, the better equipped they will be to handle the nest.

Look for distinguishing features. Like wasps, hornets have a narrow waist between their thorax and abdomen. This feature is known as the "wasp waist" and differentiates them from honeybees, which have a thicker waist between their thorax and abdomen.

Observe the black and white coloring of the hornet’s body. Unlike honeybees, which have a mix of brown and black, or yellowjackets and mud daubers, which are bright yellow and black, most hornets are black and white.

• However, some species, such as the yellow hornet and European hornet, may have different color patterns, so it’s important to pay attention to the "waist" of the insect.

Notice the size difference between hornets and wasps. Size is a key distinguishing feature between hornets and wasps, one that is easily observable whether you're up close or at a distance. For instance, the only hornet species found in the U.S. and Canada is the European hornet, which can grow to a length of about 2.5–4 cm. The maximum size of paper wasps or yellowjackets is typically 2.5 cm, often smaller than that.

• Like wasps, hornets have six legs and two pairs of wings.

Further differentiate hornets by their physical characteristics. Unlike other wasp species, hornets have a rounder abdomen near the thorax compared to other wasps. This feature is a key trait to observe when trying to identify whether you're looking at a wasp or a hornet.

Pay attention to the width of the head behind the eyes, known as the crown. The width of the hornet's crown relative to the rest of its body is wider than that of other wasp species.

Observe whether the wings are aligned along the body. Although some other members of the wasp family also fold their wings along their bodies when resting, this is another indicator to help differentiate hornets from wasps.

Note that hornets have smooth stingers without barbs. Honeybees have barbed stingers, which tear their abdomen when they sting, ultimately leading to their death. In contrast, like other wasps, hornets have smooth stingers, allowing them to sting multiple times without losing their stinger.

• While this feature helps differentiate wasps from honeybees, if you find yourself close enough to observe, it’s best to quietly back away.