Insects on car windshields were counted in Europe and China to see if their numbers have changed. Over 3,500 trips were taken, totaling 83,000 km, and 124,606 insects were found. Factors like car speed, weather, and location affected insect abundance. Insects were fewer in areas with radiation, in Western Europe compared to Eastern Europe, and in northern Europe compared to southern Europe and China. The study shows that various factors influence insect numbers, which can help us understand their populations better.