The importance of insect-induced static electricity in the atmosphere may go unnoticed.
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| A simulation based on honeybee data suggests that large locust swarms, such as the one shown here, could generate as much electricity as a storm cloud. GETTY/JOHN CARNEMOLLA |
When you talk to your crush, you might feel a spark, but living things don't need romance to generate electricity. According to a study published on October 24 in iScience, the electricity produced by swarming insects such as honeybees and locusts is an underappreciated contributor to the overall electric charge of the atmosphere.
"Atmosphere particles easily charge up," says Joseph Dwyer, a physicist at the University of New Hampshire in Durham who was not involved in the study. "Insects are tiny particles that float around in the atmosphere." Despite this, he claims that the possibility of insect-induced static electricity playing a role in the atmosphere's electric field, which influences how water droplets form, dust particles move, and lightning strikes form, has never been considered.
For a long time, scientists have been aware of the minuscule electric charge carried by living things such as insects. 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 interested in understanding how atmospheric electricity influences biology," Ellard Hunting, a biologist at the University of Bristol in England, explains. However, when a swarm of honeybees passed over a sensor designed to detect background atmospheric electricity at the team's field station, the scientists began to suspect that the influence could also flow in the opposite direction.
When other honeybee swarms passed over the sensor, Hunting and colleagues, including biologists and physicists, measured the change in the strength of the electric charge, revealing an average voltage increase of 100 volts per meter. The greater the charge produced, the denser the insect swarm.
This prompted the researchers to consider larger insect swarms, such as the biblical hordes of locusts that plagued Egypt in antiquity (and, in 2021, Las Vegas (SN: 3/30/21). Moving objects in the air, from animals to airplanes, generate static electricity. The charges of individual desert locusts (Schistocerca gregaria) were measured as they flew in a wind tunnel powered by a computer fan. Using data from other studies on locust density, the team then used a computer simulation based on honeybee swarm data to scale up these single locust measurements into electric charge estimates for an entire locust swarm. According to the researchers, locust clouds could produce electricity on a per-meter basis comparable to storm clouds.
According to Hunting, the findings highlight the importance of investigating the unknown lives of airborne animals, which can sometimes reach much greater heights than honeybees or locusts. Spiders, for example, can "balloon" on silk threads for kilometers to reach new habitats (SN: 7/5/18). "There's a lot of biology in the sky," he says, referring to everything from insects and birds to microorganisms. "It all adds up."
Though some insect swarms can be massive, Dwyer believes that electrically charged flying animals will never reach the density required to produce lightning in the same way that storm clouds do. However, their presence may interfere with our efforts to monitor for impending strikes that could harm people or damage property.
"If you have something interfering with our electric field measurements, it could cause a false alarm or cause you to miss something that is actually important," he says. While the full impact of insects and other animals on atmospheric electricity has yet to be determined, Dwyer describes the findings as "an interesting first look" into the phenomenon.
According to Hunting, this first step into an exciting new area of research demonstrates that collaborating with scientists from various fields can yield surprising results. "Being truly interdisciplinary allows for these kinds of serendipitous moments," he says.
CITATIONS
The observed electric charge of insect swarms and their contribution to atmospheric electricity by E. Hunting et al. iScience. doi: 10.1016/j.isci.2022.105241. Published online October 24, 2022.