Honey bees use frantic signals to warn of murder hornets

Many animals make sounds and calls as a form of communication, usually being associated with mating or survival. However, a new creature call has been discovered that is significantly harder to hear – the frantic survival signals of the honey bee (Apis cerana). New research from Wellesley College has documented these honey bee calls, which are used to alert hives of giant “murder hornet” attacks. 

An international team of researchers led by Heather Mattila discovered that the bees use the calls to protect themselves from hornets (Vespa soror) that are capable of wiping out entire colonies. The call has been coined as the “antipredator pipe,” with the researchers claiming it produces a distinct and chilling sound. 

“The pipes share traits in common with a lot of mammalian alarm signals, so as a mammal hearing them, there’s something that is instantly recognizable as communicating danger,” said Matilla. “It feels like a universal experience.”

“Hissing” and “stop signal” sounds have been previously studied in bee colonies, but antipredator pipes are more harsh, irregular, and with abruptly shifting frequencies. The researchers compare the sound to the panic calls that primates, meerkats, and birds make in response to predators.

“[Bees] are constantly communicating with each other, in both good times and in bad, but the antipredator signal exchange is particularly important during dire moments when rallying workers for colony defense is imperative,” wrote the study authors. 

To protect the hive from giant hornets, the signal results in an abundance of bee activity at the hive entrance, in addition to defense mechanisms such as the spreading of animal dung and forming collective “bee balls.”

The calls have been studied through the audio and visual recordings of Asian honey bees in Vietnam, ultimately resulting in over 21 hours of signals. The sounds were described as noisy and frenetic, with hive chatter increasing eight fold in comparison to when there was no danger present.

“This research shows how amazingly complex signals produced by Asian hive bees can be,” said study co-author Gard Otis. “We feel like we have only grazed the surface of understanding their communication. There’s a lot more to be learned.” 

According to the study, the antipredator pipes resulted in the bees raising their abdomens, buzzing their wings, running frantically, and revealing their pheromone-producing nasonov gland. The totality of this behavior ultimately suggests that the bees attract the attention of their nestmates through the generation of multiple types of information.

The research is published in the journal Royal Society Open Science.  

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By Calum Vaughan, Earth.com Staff Writer