By 2002, drivers in London, England, were spending as much as half their commuting time stalled in traffic, contributing to much of the city centre’s dangerous particulate pollution. To deal with a growing population, increasing gridlock and air quality concerns, the city implemented a congestion charge, using a photo-based licence-recognition system.

According to an African proverb (and the Dalai Lama), “If you think you’re too small to make a difference, try sleeping in a closed room with a mosquito.” The saying implies that even when we feel insignificant and powerless, we can create a buzz. But mosquitoes and other tiny critters can literally have a huge impact.