According to researchers, moths and other flying insects are drawn to artificial lights at night not because they are attracted to the light itself, but because the light disrupts their navigation systems. Sam Fabian, co-author of a study published in the journal Nature Communications, explains that moths and other insects instinctively tilt their bodies toward light to reorient themselves as the sky is lighter than the ground, even at night, NPR reports. Fabian, an entomologist at Imperial College London, praises this behavior as finely tuned and effective, except when artificial lights are introduced.
Researchers used motion-capture video with sensors attached to moths and dragonflies to observe the flight patterns of confused insects circling lights for extended periods, as reported by the AP. Harvard entomologist Avalon Owens, who was not involved in the study but specializes in the effect of artificial light on insects, expressed excitement about the discovery. Owens tells NPR, “We’ve probably been wondering why moths fly to lights since the invention of fire. The fact that after, like, literally millennia we have a new observation on this very old phenomenon is just absolutely buck wild to me.”
Fabian’s research indicates that artificial light does not attract insects from the surrounding area, but rather traps those that fly by, as reported by the Guardian. He compares it to having a net. Light pollution is widely believed to contribute to the significant decline in insect populations, and Fabian believes that this study could aid in conservation efforts. The study also found that insects are less disoriented by lights that are pointing downward. “If you are going to have lights at night, you really want them to be shrouded and not chucking loads of light out sideways, and especially not upwards into the atmosphere,” he says. (More insects stories.)
