Headline: In 2021, 654 volunteers began counting insect splats on cars across the UK; by 2024, the survey recorded a 62.5% drop

There's a certain summer road-trip memory that most people over a certain age may immediately relate to: pulling into a gas station, pulling out the squeegee, and scraping a windshield that's looked like a crime scene after a few hundred miles of summer driving. Put the same question to a college student today, and the answer is more confused than nostalgic. The culprit isn't that young drivers spend less time on the road with their windows down; it appears, rather, that there are just fewer insects left to strike their windshields, come to think of it.

That's what the new data from UK entomologists suggests, and it has generated considerable interest this year. The Bugs Matter 2024 report, published by Kent Wildlife Trust and the invertebrate charity Buglife in a citizen-science survey that began in 2021, found that the number of flying insects recorded on volunteers' license plates across the UK fell by 62.5% between 2021 and 2024. The study, which recruited 654 volunteers to attach a standard grid to their number plates and report every journey taken in a specially designed app, has so far tracked tens of thousands of journeys around the UK. The decline was not isolated to just one region, but stretched across England (62%), Wales (64%), Scotland (over 65%) and Northern Ireland (55%). The national figure isn't a simple average of the four regions; it comes from a statistical model run across the full dataset that adjusts for factors like journey speed, distance, and land type, which is why the regional numbers don't need to line up with the national one through basic arithmetic.

The bug-splat problem is not limited to the UK


Here's the twist that makes this worth an American's time: this isn't just a uniquely British phenomenon, or a new one either. The so-called "windshield phenomenon" has long been anecdotally noticed by American drivers, well before anyone tried to formally track it. What's more significant is that where researchers tracked it down, the US doesn't look particularly impressive.

According to a landmark 2021 review article titled “Insect decline in the Anthropocene: Death by a thousand cuts,” published in the Proceedings of the National Academy of Sciences and led by University of Connecticut entomologist David Wagner, along with collaborators Eliza Grames, Matthew Forister, May Berenbaum and David Stopak, declining numbers of insect species are actually due to a confluence of factors rather than a single one: loss of habitat, industrialized agriculture, pesticide use, invasive species, light pollution, and climate change all play a role. Those same drivers are still cited by more recent research, though the review itself reflects the state of the science as of 2021, not the past five years. The review singles out two iconic creatures familiar to American readers: honeybees, whose colony losses have dominated headlines for over a decade, and monarch butterflies, which have had their annual migration across the Midwest made significantly harder by the loss of milkweed habitat.

It's not quite an apocalypse everywhere, though

Give the bugs a break; while these figures suggest a rapidly deteriorating global insect crisis, it's important to note that for all the ways the insect populations are shrinking on land, they're still showing up in places like freshwater. A widely-cited 2020 study titled “Meta-analysis reveals declines in terrestrial but increases in freshwater insect abundances,” published in the journal Science by Roel van Klink and others that pooled together 166 long-term ecological insect surveys from over 1,600 sites around the world, found that terrestrial abundance of insects declined by an average of 9% per decade, which is a serious, but far short of a "half the bugs gone in a generation" decline.

Oddly, freshwater insects actually saw their numbers go up by about 11% per decade: a sign, perhaps, that decades of clean-water legislation in wealthier nations are paying off for these species, while their land-based cousins have had a much harder time. At the same time, the authors were careful to point out that trends varied enormously from one site to the next, and that the findings were largely dominated by sites in North America and parts of Europe, meaning the US wasn't a mere footnote, but one of the main players in this study.

On the specific question of how a population can fall by almost two-thirds in just three years: the Bugs Matter researchers themselves flagged this as unusually fast, and attribute it to two effects stacking on top of each other: a slower, decades-long background decline (the same survey's 2004-to-2023 comparison found a 77.6% drop, or about 43% per decade) layered under a sharper short-term dip tied to extreme UK weather in 2022 and 2023. Broken down year by year, the survey found drops of 27.5% in 2021–2022 and 43.8% in 2022–2023, before the rate of decline slowed sharply to just 8.0% in 2023–2024, which compounds out to the 62.5% figure, rather than representing one uniform, unprecedented crash.

Why this should bug you more than it does

It's easy to think of insect decline as just another tragedy of the commons, one that rightly belongs on a short list of sad things that we feel vaguely guilty about but ultimately powerless to do anything about. But bugs represent the unpaid labor force behind a massive fraction of the food chain system; they provide pollination, predatory control of pest species, and are even a food source for the birds and fish higher up the food chain. A quieter windshield might sound like a small comfort on a long drive, but it's also a strange thing to feel nostalgic for: the bugs, and for the sheer number of them that once populated our roads.