Bees have unique personalities that determine whether they sting

A honeybee colony seems like a perfect model of unity. Inside the hive, thousands of individuals work in rhythm. Foragers seek nectar. Water collectors hydrate the group. Ventilators fan their wings to cool the brood. Guard bees monitor the entrance.

In this coordinated dance, defense is critical – but personality plays a role, and not all bees choose to sting.

What triggers a bee to sting? Why do some launch themselves into action while others hold back? A new study from the University of Konstanz has explored these questions.

Researchers discovered that not only do bees differ in their readiness to sting, but their personalities remain consistent across time and context. The hive may move as one, but decisions start within the individual.

Bees choose to sting or abstain

Doctoral student Kavitha Kannan and neurobiologist Morgane Nouvian led the research at the University of Konstanz. To examine stinging behavior, they needed a reliable group. They selected guard bees – those that are naturally closer to the frontlines.

“Basically, you can expect that, simply by the distribution of tasks, a collector will have a different stinging behaviour than a guard. As we wanted to exclude as many influencing factors as possible, this selection was the first logical step. We were then able to gradually test other influencing factors,” explained Kannan.

The bees were exposed to a rotating dummy that simulated a predator. The setup allowed repeated trials without harming the bees. When a bee stings in natural conditions, its stinger is lost and it dies. Here, the bees could engage or abstain multiple times without being harmed. Each action or lack of action was logged.

Alarm scents don’t trigger all bees

In honeybees, a sting is more than a weapon. It is a call to arms. When a bee stings, it releases a complex scent signal known as the sting alarm pheromone (SAP), which is primarily composed of iso-amyl acetate (IAA).

This alerts others and encourages them to join in the group defense. As more bees respond, the concentration of IAA increases. Eventually, the response declines – a strategy that may ensure not too many casualties occur.

The study found that SAP does influence bees, but not equally. When exposed to synthetic IAA, bees showed varied reactions. The presence of this signal raised the odds of stinging – but some bees still held back.

“Ultimately, it turned out that although these factors had an influence, they did not impact the predictability of individual stinging behavior,” said Nouvian. The bees that chose to sting in one trial often did so again. Others remained passive, regardless of the alarm.

Bee personality and stinging behavior

To probe deeper, the researchers tracked bee responses over four repeated trials. The results were striking. Stinging behavior stayed consistent in most individuals. Some stung every time, others never stung, and very few wavered between the two choices.

Even more interestingly, the bees showed greater consistency in behavior when the time between trials was less. This suggests that internal states – perhaps neurological or hormonal – affect decisions. A bee wasn’t flipping a coin each time. It was acting from a semi-stable inner condition.

This state dependence was especially clear when patterns like 1−0−1−0 (stinging, not stinging, stinging, not stinging) were rare. Instead, most bees either kept attacking or kept abstaining. These temporal patterns implied that bees make evaluations based on more than stimulus alone – they carry a mood-like persistence.

Peers aren’t always influential

Bees are famously social. Still, the presence of another bee had a surprising effect. Rather than encouraging aggression, it reduced it. Pairs of bees were less likely to sting than solo bees, even when faced with the same threat.

This finding challenges currently-held assumptions. Larger groups don’t necessarily mean higher per-bee aggression. In fact, the data aligns with older studies suggesting that larger colonies can show less per-capita defense.

When tested in pairs, real bees stung less than would be predicted by combining data from singles. The effect appeared again, even when both bees could detect IAA. “Pairs as entities did [respond to IAA] (z = −4.327, p < 0.001) … individual bees within pairs (z = −3.68, p < 0.001),” the research paper noted.

Yet, the experts also found that SAP, when released naturally by one bee, could recruit another. The first bee’s sting raised the odds that its partner would follow. But over multiple exposures, this recruitment faded. Responsiveness to IAA dropped, trial by trial. Even social signals have an expiry date.

Bees with gentle personalities sting less

Another part of the study tested whether bees adjust based on their companions’ personalities. After identifying aggressive and gentle bees, the team mixed them in various combinations. Would gentle bees become bolder when placed among aggressive peers?

The answer was no. Bees classified as gentle stayed that way, even in groups full of stingers. Aggressive bees also stayed true to type. The only thing that influenced changes was the SAP level in the arena. More SAP raised the chance of stinging, less reduced it.

These results reveal that honeybees don’t mirror the behavior of those around them. They react to chemical signals, not peer pressure.

“We propose that [Lecomte’s] results were rather the consequence of the reduced group size,” noted the researchers, questioning earlier claims about social inhibition among bees.

Bees resist group influence

What does this mean for our understanding of bee society? This study breaks the idea of a hive acting as one. Each bee carries an internal threshold. That threshold can be nudged by alarm pheromones or dulled by time. It can be lowered by a sense of threat or raised by the presence of others.

Still, the final decision lies with the bee. Stinging isn’t a hive decision. It’s an individual one, shaped by subtle internal states and stable personality.

“That bees stop responding to the SAP but not to the threat itself might be another example of social information being less valued than personal information,” the researchers suggested.

Future research on honeybee behavior

This study paves the way for deeper research into honeybee behavior. By proving the stability of individual responses, it opens doors for exploring the biological roots of personality. Future work could look into the neurobiology of aggression or the hormonal triggers behind it.

The hive may appear unified, but it is made of diverse minds. Some are ready to die for the colony. Others prefer to wait, even when the alarm is raised. Both types are part of nature’s plan – and together, they balance risk and survival.