July 8, 2025, 1:23 pm | Read time: 8 minutes

Normally, honeybees pose no threat. However, in certain situations, even the most docile colonies can suddenly become aggressive. This recently happened in France, where bee colonies on a hotel roof attacked 24 people. But why did the insects suddenly attack? PETBOOK editor Saskia Schneider, a biologist and beekeeper, explains possible reasons.

The bee colonies were located on a hotel roof and injured a total of 24 people–three of whom had to be treated in the hospital for allergic reactions, as reported by the regional newspaper “La Montagne.” These were neither the notorious killer bees nor particularly aggressive colonies. The beehives had been there for ten years. So why did the bees suddenly attack people?

Are Some Honeybees Particularly Aggressive?

The species of bee kept by beekeepers in Europe is the European honeybee, Apis mellifera. It is considered gentle, although–as with all living creatures–there can be individual differences. Some colonies are a bit more “sting-happy” than others. However, beekeepers usually ensure gentle bees through selective breeding, as the goal is to work with the colonies without protective clothing whenever possible.

Colonies are considered particularly gentle if their bees do not immediately fly up and sting when disturbed. But even sting-happy colonies generally do not attack people who are near the hives–as beekeepers call the bee homes. However, there are situations where bees do indeed attack people–even colonies that rarely sting otherwise.

Why Bees Suddenly Attack People

As a beekeeper, I own several bee colonies myself. Some of them are a bit more “on the ball” than others. But even with my gentle colony, it has happened that the bees attacked from one minute to the next. After five minutes, it was all over, and the little insects were back to minding their own business–as if nothing had happened. Why my colony suddenly attacked me, I do not know. Generally, there are various reasons why bees might attack people.

Thunderstorms

One of the most common reasons why bees, which are usually gentle, suddenly become irritable is an approaching thunderstorm. The animals can often sense this hours in advance and react accordingly. If you are near the colonies, the risk of being stung is high. However, in my experience, it is usually only individual bees that sting. It is different when you open the colonies. Then an attack can indeed occur.

Sudden Weather Changes

Not only thunderstorms but also sudden weather changes can be the reason why bees suddenly attack. Humid weather, in particular, seems to bother the little insects. However, I have observed this phenomenon extremely rarely in my colonies.

Declining Forage

Beekeepers refer to the food collected by bees, especially nectar, pollen, and honeydew, as forage. There are usually various large forages throughout the year. In spring, for example, it’s rapeseed, and in summer, it’s linden–plants that provide large amounts of nectar and pollen.

In late summer, this supply drastically decreases–and the mood at the colonies shifts. The bees are now more focused on defending their supplies–something beekeepers also notice. Sometimes the mood of the bees can shift so much that they attack people who are near the colonies.

Robbing

When the supply of nectar and pollen decreases, bee colonies may start stealing from their neighbors. This can end in what is called robbing. In this scenario, the bees of one colony storm the honey supplies of another. Weaker colonies, which are less able to defend themselves, are particularly affected. This causes stress and can make the insects quite irritable.

Attacks by Predators

Even though there are few bears left in Europe that plunder bee colonies, other animals like woodpeckers or mice can also cause stress for bees. If a colony is repeatedly attacked, the bees eventually become quite aggressive and attack anything that approaches the colony.

The Asian hornet, Vespa velutina, which is feared by beekeepers, could also play a role here. At least, this was suspected for the bee colonies in the incident in France. The hornet species was introduced from Asia to Europe and has also arrived in Germany in recent years. Unlike our native hornets, Vespa velutina launches full-scale attacks on honeybee colonies and can visibly reduce the number of bees, thus weakening the colonies.

Although I am not aware of any cases where colonies became suddenly aggressive and attacked people due to an Asian hornet attack, this behavior is conceivable.

Vibrations

Another reason why bees attack people near the hives is vibrations. Typically, lawnmowers are the trigger. Almost every year, I receive reports that our bees stung someone who was trying to mow the lawn near the colonies. But other devices that produce loud vibrations can also drive bees into a frenzy.

Scents

Occasionally, I take a group of interested people to the colonies to show them the work with the bees. While everyone stands around the open colony and the bees lazily fly around, there is sometimes that one person who is chased away and stung by the insects.

Often, this is due to scent. Shampoos or perfumes, in particular, can contain fragrance components similar to those of the so-called alarm pheromone. Bees release this hormonal scent to alert their sisters and mark the enemy. It also causes other bees to sting more readily and go on the attack.

How Often Do Bees Attack People?

There is no statistic on the frequency of European honeybee attacks on people. It probably happens too rarely. In my experience, most people are stung by bees because they accidentally step on or crush the insects.

I have only experienced bees deliberately attacking people when the colonies were actively being worked on. And then it mostly affects the beekeeper directly. But for bees to launch an attack from the closed colony on passersby who are simply near the hives is, in my opinion, extremely unlikely.

By the way, a swarm of bees generally poses no danger. These are often found hanging in trees or other high places, especially in April and May. Even though such a large mass of bees can be impressive, there is no need to be afraid. These bees are looking for a new home and have neither brood nor supplies to defend.

How to Behave During a Bee Attack

If you are attacked by one or more bees, you should leave immediately. If bee colonies are nearby, quickly increase the distance from them. Cover exposed skin if possible. Protect your face, as bees react to the CO₂ emitted from the nose and mouth.

Generally, bees respond to a disturbance directly nearby. However, it can happen that individual bees follow you for a longer time, especially if scents play a role. If children or people with allergies are affected, it is legitimate to kill a bee to prevent greater harm.

Behavior Tips for Encounters with Bee Colonies

I want to emphasize again that attacks by bee colonies are rare. It is generally completely safe to be near beehives. However, respect should be maintained, and some rules should be followed:

• Do not create vibrations: Especially lawnmowers can cause even the gentlest bees to attack people. But rattling motorcycles can have the same effect.
• Do not stand in front of the flight hole: If you are brave and want to see bee colonies up close, always approach from behind and do not stand directly in the flight path. Some colonies feel disturbed by this. Additionally, there is a high risk that a bee might fly into your head, get caught in your hair, panic, and sting.
• Do not blow on them: Blowing on bees to drive them away is a bad idea. The CO₂ in your breath can cause the animals to sting.
• Do not swat at animals or crush bees: If you want to drive away a bee that is too persistent, either move away slowly or do so with calm movements, essentially pushing the insect away in the air (this also helps with wasps). Swatting at a bee and crushing it releases an alarm pheromone, signaling to other bees: Here is the enemy!
• Move slowly: In general, you should behave calmly around bee colonies. Especially near the flight holes, frantic movements can prompt some bees to sting.

More on the topic

Individual Character Why Some Bees Are More Prone to Sting Than Others

After the attack Expert: ‘Orcas purposely sink sailing yacht!’

Defensive Behavior Why Do Ants “Pee” on Humans? Biologist Explains

Conclusion: Bees Rarely Attack People

Attacks by European honeybees are extremely rare. Most bee colonies are bred for gentleness, and even “sting-happy” colonies usually only attack when the hives are opened. So when bees attack people, it mainly affects beekeepers. This makes the case in France all the more unusual, as the colonies were several meters high on the roof. They launched a targeted attack–and that for 30 minutes.

An attack by the Asian hornet was suspected as the trigger. However, I find this extremely unlikely. Without knowing more details, I would rather suspect a disturbance near the attacked passersby, such as strong vibrations caused by road construction. However, it cannot be ruled out that the incident was triggered by a hornet attack.