Light pollution is the excessive use of artificial light that interferes with natural cycles and patterns of light and dark. It is caused by the overuse of energy-inefficient lighting, such as streetlights and security lights, that scatter light into the night sky, making it difficult to see stars and other forms of natural light. Light pollution can also disrupt the natural behavior of nocturnal animals, including birds and insects. To reduce light pollution, cities and towns should switch to energy-efficient lighting, such as LED lights, and use timers and motion sensors to reduce light waste.