Murder hornets didn't turn out to be the existential threat to humanity we feared them to be in 2020, but similar hornets are still scary if you're a honeybee. A swarm of Vespa soror—a sister species to Asian giant hornets, or murder hornets—can destroy a beehive in hours. As The New York Times reports, honeybees in Southeast Asia have developed a disturbing defense mechanism against hornet onslaughts: "screaming" at the top of their wings.

In a study published in the journal Royal Society Open Science, an international team of researchers describe the haunting sound of an Asian honeybee nest under attack. In the presence of Vespa soror, the bees will lift their abdomens and vibrate their wings to produce a call known as an "antipredator pipe." Scientists have compared it to the shrieks and cries of larger animals in distress. You can hear what a screaming bee sounds like in the video below.

The new study was borne out of research into a different kind of bee behavior in 2013. Asian honeybees are known to ward off Vespa soror and Vespa mandarini (murder hornets) by spreading animal feces around their hives. Heather Mattila, a behavioral ecologist at Wellesley College, was studying this defense tactic in Vietnam when she noticed a strange sound that coincided with the arrival of Vespa soror. Video and sound recorders placed around the nest confirmed that the bees made the shrill noise in response to the predators.

It sounds like a distress call, but researchers don't have enough data to pinpoint the exact function behind the scream. It could be a kind of alarm the bees harness to alert other members of the colony to danger. The fact that the screams crescendo when the hornets reach the entrance to the hive supports this theory.

Asian honeybees are more elusive than their European counterparts, which means much of their world remains a mystery to science. Here are some general facts about bees we do know.

[h/t The New York Times]