This summer, you may have wondered why you are seeing so few insects squished on your car's windshield compared with a road trip several years ago. This is because insects are declining globally at an alarming rate.

One extensive citizen science survey looked at insect numbers over several years by tracking insect deaths on car license plates. Participants were asked to clean their license plates before a journey, then photograph them afterward and count the number of bugs killed.

The survey was conducted from 2021 to 2025. It found the number of flying insects sampled on vehicle license plates across the UK had fallen by 60% in five years. Analysis of records from more than 25,000 journeys showed an annual average decline in bug splats of 19% since the survey began in 2021.

Some people may look at these statistics and wonder why they should care. But the decline of insect life is a significant cause for concern. It's not just in the UK that we are seeing declines, but also across Europe and in tropical rainforests, including some of the most biodiverse spots on the planet. Agricultural land is seeing some of the worst effects.

There are an estimated 10 quintillion (10,000,000,000,000,000,000) insects alive on this planet, with more than a million described species and estimates of millions more yet to be discovered. But we are losing insects far faster than other animals, and at an unprecedented rate.

A review in 2019 suggested 40% of insect species are threatened with extinction. Ants, bees and wasps (Hymenoptera), butterflies and moths (Lepidoptera), and dung beetles are thought to be the most affected. More recent reviews show similar declining trends on a global scale.

Why are insects disappearing?
The reasons for losing our insects include habitat loss, disease, pollution and pesticides. Agriculture is a major concern because converting land to farming can remove existing habitats—essentially removing some insects' homes. Agricultural chemicals, such as pesticides designed to kill agricultural pests, are also negatively affecting the nontarget insects that we want to protect.

Climate change is a major concern and one that potentially exacerbates other factors. When it's hotter, water availability becomes more difficult, plants become more stressed and food becomes harder for insects to find...