"Think of it as a citronella candle on wheels. Mosquito-bourne illnesses are a growing issue in Thailand's slums, with the incidence of dengue fever tripling in 2015. To battle the glut of diseased pests, a Thai charity, the Duang Prateep Foundation, and its agency BBDO Bangkok, repurposed another abundant local feature -- motorcycle exhaust fumes. The result is Moto Repellent, an anti-bug filter that riders--ubiquitous in Thailand--can attach to their tailpipes. The filter contains mosquito repellent oil that, when mixed with the heat from the engine's spent fuel, produces a special smoke that can deter mosquitos for up to three meters."