Insect swarms may generate as a lot electrical cost as storm clouds

You may feel a spark when you talk to your crush, but beings don’t need romance to generate electricity. A study published Oct. 24 in iScience suggests that the electricity naturally produced by swarming insects like honey bees and grasshoppers is an unappreciated contributor to the atmosphere’s overall electrical charge.

“Particles in the atmosphere charge up easily,” says Joseph Dwyer, a physicist at the University of New Hampshire at Durham, who was not involved in the study. “Insects are small particles that move around in the atmosphere.” Still, the possibility that insect-induced static electricity plays a role in the atmosphere’s electric field, which affects how water droplets form, dust particles move, and lightning strikes is not yet raised been considered, he says.

Scientists have long known about the tiny electrical charge carried by living things like insects. However, the idea that an electric bug aloo could change the charge in the air on a large scale came to researchers by accident.

“We were actually interested in understanding how atmospheric electricity affects biology,” says Ellard Hunting, a biologist at the University of Bristol in England. But when a swarm of honey bees at the team’s field station passed a sensor meant to detect atmospheric background electricity, the scientists began to suspect the influence might be flowing the other way as well.

Hunting and colleagues, including biologists and physicists, measured the change in the magnitude of the electrical charge as other swarms of honey bees passed the sensor, showing an average rise in voltage of 100 volts per meter. The denser the swarm of insects, the greater the charge generated.

This inspired the team to consider even larger swarms of insects, like the biblical hordes of locusts that plagued Egypt in ancient times (and in 2021 Las Vegas (SN: 3/30/21)). Flying objects, from animals to airplanes, build up static electricity as they move through the air. The team measured the charges of individual desert locusts (Schistocerca gregaria) as they flew in a wind tunnel powered by a computer fan. Using data on locust density from other studies, the team then used a computer simulation based on the honey bee swarm data to extrapolate these individual locust measurements into electrical charge estimates for an entire locust swarm. Locust clouds could generate electricity per meter that is on par with that in thunderclouds, the scientists report.

Hunting says the findings underscore the need to explore the unknown life of aerial animals, which can sometimes reach much greater heights than honeybees or grasshoppers. Spiders, for example, can “balloon” on silk threads for miles above the earth to reach new habitats (SN: 7/5/18). “There’s a lot of biology in the sky,” he says, from insects and birds to microorganisms. “Everything fits together.”

Though some swarms of insects can be immense, Dwyer says electrically charged flying animals will likely never reach the density required to produce lightning like storm clouds do. But their presence could interfere with our efforts to watch out for impending strikes that could injure people or damage property.

“If something messes up our electric field measurements, it could set off a false alarm,” he says, “or it could cause you to miss something important.” While the full effect that insects and other animals have on atmospheric electricity remains to be seen Dwyer says these results provide “an interesting first look” at the phenomenon.

According to Hunting, this first step into an exciting new field of research shows that collaborating with scientists from different fields can yield shocking insights. “Being truly interdisciplinary,” he says, “allows for such random moments.”