While Ellard Hunting and fellow researchers were out studying the weather at a field station in England, they noticed something unexpected on one of their instruments. Though there was no storm approaching, the scientists’ electric field monitors recorded a curious uptick in atmospheric electric charge.
Nearby, western honeybees that lived in on-site research hives were swarming as they attempted to find a new home. When the team took a closer look at their data, they discovered that the swarming honeybees had created an atmospheric electric charge—and that their charge was similar to that of a thunderstorm cloud. The researchers shared more details about their findings this week in the journal iScience.
“This makes it the first report of biology as a source of biogenic space charge, which can be as relevant as physical phenomena such as clouds,” says Hunting, one of the study's authors and a biophysicist at the University of Bristol in England, to Popular Science’s Laura Baisas.
Scientists had known that individual bees carry a small charge while flying through the air, caused by the friction of their body parts against the air and each other. It’s similar to how rubbing a balloon on a piece of fabric or shuffling sock-clad feet across a rug creates static electricity. Scientists believe a bee’s charge helps pollen stick to it and signals to other bees which flowers have already been visited.
But until now, researchers had never recorded such a high voltage among swarming honeybees. To explore the phenomenon further, the scientists set up video cameras and additional electric field monitors, then waited for nearby bees to group together. Their devices were able to capture three swarms for around three minutes each, measuring the density and electric field of each one.
The honeybee swarms produced an electric charge that ranged from 100 to 1,000 volts per meter, the researchers found. And the greater the density of the swarm, the greater the charge it produced.
As far as electricity generation goes, a bee swarm’s charge isn’t too impressive: It would take about 50 billion bees to power an LED light, Popular Science reports. But compared to the charges produced by common weather events, the bees’ charge density was six times greater than an electrified dust storm and eight times greater than a thunderstorm cloud.
Using the honeybee data, the researchers created a model to predict the potential atmospheric electric charge of other insects, including locusts, moths and butterflies. “Locusts swarm on biblical scales,” Liam O’Reilly, a co-author and biologist at the University of Bristol, says in a statement. Clouds of these insects can span up to 460 square miles and contain roughly 80 million locusts per square mile. The researchers predict locusts would have a much bigger influence on the atmosphere compared to honeybees.
Scientists aren’t sure whether a swarm’s electric charge serves any purpose. But they hope to continue exploring how biology influences physics and are curious to know if something similar is happening with other wildlife, such as birds and bats.
“These are all interesting questions that this paper opens to investigate,” says Victor Manuel Ortega-Jiménez, a biologist at the University of Maine who was not involved in the study, to New Scientist’s Corryn Wetzel.