Spotting an Asian hornet nest: the tell-tale signs

Key takeaways

Why it's important: an early reported nest means up to 13,000 hornets and 500 to 1,000 future queens will not disperse in the fall. At a neighborhood level, the impact is considerable.

The 6 signs that betray a nearby nest:

• A regular back and forth of hornets in the same direction
• Repeated air corridors above beehives, flowerbeds, or fruit trees
• A hovering flight in front of beehives (absolute sign)
• Pieces of insects on the ground under the same tree (butchering area)
• A continuous, low hum in a specific area
• Regular noises in a chimney, roller shutter, or wall

What NOT to do: approach within 5 meters of a nest, try to destroy it yourself, confuse it with a European hornet nest (which is beneficial and sometimes protected).

If you identify a nest: photograph it from a distance, report it to your local town hall, and call a certified pest control professional.

Understanding the two types of nests

The Asian hornet builds two nests during its season, and they look completely different. For a complete description of the different types of nests, you can also consult our dedicated page on Asian hornet nests: how to identify them.

The primary nest (March to June)

• Size: from a tennis ball to an orange, sometimes up to the size of a melon
• Shape: spherical, opening downwards
• Color: grayish, papier-mâché appearance
• Location: low and sheltered: under an awning, in a shed, under a roof overhang, in a roller shutter box, in an unused chimney, sometimes under garden furniture

This is the nest the queen builds alone after hibernation. At this stage, it contains a few dozen individuals at most. It's the easiest to neutralize because it's low and sparsely populated. But it's also the most discreet.

The secondary nest (July to November)

• Size: from a bowling ball to a basketball, up to 80 cm in diameter by the end of the season
• Shape: spherical or elongated pear shape, opening on the side (distinctive sign!)
• Color: grayish, sometimes light beige
• Location: very high up, usually between 10 and 20 meters, attached to tree branches, more rarely under a roof frame or in a building

This is the nest the colony builds after the July relocation. It can contain several thousand individuals by the end of the season. Much more visible, but much more difficult to neutralize due to its height.

Key distinctive sign: the side opening of the secondary nest is unique to the Asian hornet in Europe. All other European wasps and hornets have nests with a bottom opening. If you see a large, ball-shaped nest with a side entrance, you've found your culprit.

Indirect signs of a nest's presence

Most of the time, you won't see the nest until you've seen the signs. Hornets betray their presence long before the nest itself is identified. Here are the clues to look for.

Sign #1: Regular comings and goings of black insects

This is the number one clue. If you notice Asian hornets (dull black body, yellow leg tips, orange ring on the abdomen) that are always moving in the same direction, you are near a nest. To distinguish the Asian hornet from other species, consult our guide to differentiate European hornet, Asian hornet, and wasp.

Observation method:

• Stand 5 to 10 meters from an area where you've seen several hornets
• Observe for 15 to 20 minutes, using binoculars if necessary
• Note the direction of arrival and departure

Sign #2: Repeated "air corridors"

Asian hornets almost always use the same flight paths between the nest and their hunting grounds. These are called air routes.

Where to look for them?

• Above a beehive or apiary
• Above a flowerbed heavily visited by pollinators
• Near a composter or water point
• Near fruit trees (cherry, apple, grapevines)

If you see hornets always flying in the same direction above one of these points, follow the trajectory — it will lead you to the nest.

Sign #3: Hovering in front of beehives

This is the pathognomonic sign: no other insect in France does this. The Asian hornet hovers 20-30 cm in front of a beehive entrance and waits for foraging bees returning loaded with pollen, to catch them in mid-flight.

If you are a beekeeper or have beehives in your neighborhood, this is the absolute alert sign. A nest is necessarily within 1 to 3 km.

Sign #4: Pieces of meat or insects on the ground

Asian hornets butcher their prey on the spot before carrying the thorax (rich in protein) back to the nest. If you regularly find, under the same tree, scattered bee abdomens, heads, or wings on the ground, it is probably a butchering area located under a frequented branch.

Look for the nest just above, in the canopy.

Sign #5: A continuous, discreet hum

Approach a suspicious area (without entering the 5-meter perimeter). If you hear a regular, low hum, like the purring of an electrical appliance, it's an active nest. The more mature the colony, the more audible the sound.

Absolute precaution: this test is done only at a distance and beyond 5 to 10 meters. Within 5 meters of a mature nest, the risk of a collective attack is high.

Sign #6: Humming in a chimney, shutter, or wall

This is the alarm signal for a primary nest (spring) or a secondary nest installed in a building. If you hear:

• A continuous hum coming from an unused chimney
• Regular noises in a roller shutter box
• A dull humming sound in a hollow wall or attic

Do not open anything. Close the duct or access area from the inside and call a professional. Intervention in a confined space is delicate and dangerous to improvise.

Priority areas to inspect

The Asian hornet has its habitat preferences. Here is a list, in order of probability, of places to check in your garden and around your home.

Close inspection areas (primary nest in spring, sometimes secondary nest)

1. Under roof overhangs and eaves
2. Garden sheds, wood sheds, open garages
3. Roller shutter boxes, especially on the north or east side (shaded)
4. Unused chimneys
5. Attics and ventilated lofts
6. Old empty beehives or forgotten nucs
7. Dense bushes near homes (privet hedges, laurels)
8. Under unused garden furniture

High inspection areas (secondary nest in summer-autumn)

1. Canopies of trees over 10 m (oaks, plane trees, pines, ash trees)
2. Wood edges and forest path borders
3. Riverbanks and watersides
4. Clumps of trees in the middle of meadows
5. Isolated trees in the middle of a garden

Buzette's tip: secondary nests are often invisible as long as the leaves are on the trees. Many are only spotted in October-November, when the leaves fall, by which time the colony is already at its peak and has already begun to release its queens. Hence the importance of looking for indirect signs from summer onwards.

The systematic inspection method

Rather than randomly searching, I suggest a 4-step method.

The best time to inspect

• Early morning (8-10 AM) or late afternoon (5-7 PM), when hornets are active but the sun isn't too high
• In clear, calm weather (no strong wind, no rain)
• Ideally several days in a row to confirm observations

Useful equipment

• Binoculars (8x or 10x) to observe canopies without getting too close
• Notebook and pen to note directions, frequencies, times
• Smartphone for remote photography and geolocalization
• Light-colored clothing (yellow, pale green): hornets are less reactive to light colors than dark colors

The inspection route

1. Walk around the entire perimeter of your home (all 4 facades)
2. Inspect the strategic points listed above
3. Stay 5 to 10 minutes at each point of interest
4. Note everything: frequency of passages, direction, flight height
5. Then expand to the rest of the garden and surrounding areas (hedges, neighboring trees)

Triangulation

If you observe hornets coming from several different directions, you can triangulate the approximate position of the nest:

• Note 2 or 3 different trajectories
• Mentally (or on a map) draw the lines
• The intersection point gives you the approximate area of the nest

What you absolutely must avoid

NEVER approach within 5 meters
At this distance, the risk of a collective attack is real, especially for mature nests. Asian hornets defend their nests with aggressiveness and coordination. An attack can involve several dozens of individuals simultaneously.

NEVER try to destroy a nest yourself
Whether with a jet of water, a general insecticide product, burning, a pole, or any other "homemade" method: it is dangerous and ineffective. Every summer, dozens of people are hospitalized for attempting such ventures.

Do not confuse with a European hornet nest
The European hornet (beneficial, sometimes protected) builds smaller nests, open at the bottom, often in cavities (hollow trees, attics). Do not destroy it: it is valuable for biodiversity. In case of doubt, ask a professional or local expert for identification.

Do not confuse with a wasp nest
Wasps generally build smaller nests, under shelter, made of light papier-mâché, sometimes visible. They do not pose the same threat as the Asian hornet to biodiversity.

What to do if you have identified a nest?

1. Do nothing. Keep your distance and alert the right contacts.

2. Photograph from a distance (zoomed in, never by approaching): the nest, the host tree, the surroundings. Note the estimated height.

3. Report the nest:

• The INPN Espèces application from the Museum
• Your local town hall (which may cover all or part of the destruction cost depending on the municipality)
• The GDSA (Groupement de Défense Sanitaire Apicole) of your department

4. Call a certified pest control professional. Prioritize professionals trained in high-altitude intervention with telescopic poles and appropriate insecticides. Expect to pay an average of €80 to €150 per intervention depending on height and accessibility.

5. Keep the photo and location: they contribute to national mapping and scientific monitoring of the invasion front.

Patient observation, your best weapon

Spotting a nest is neither luck nor chance: it's patient, methodical, and well-equipped observation. Nature always leaves clues – you just need to know how to read them.

The Asian hornet is a formidable adversary, but it has a weakness: it is predictable. Same air corridors, same hunting habits, same nesting sites. When you know what to look for, you find it.

And every reported nest means up to 13,000 hornets and 500 to 1,000 future queens that will not disperse in the fall. At the scale of a neighborhood, a village, a municipality, that's huge.

Bzzz see you soon, Buzette.

Want to act proactively, even before a nest forms near you? Discover Hornet EcoTrap, the selective trap made in France that intercepts queens in spring – the most effective strategy to prevent a nest from forming in your garden.

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