A recent study highlights the implications of urban outdoor lighting on both human sleep and natural ecosystems. With cities overflowing with streetlights, traffic signals, and decorative lighting, the resulting ambient light can extend far beyond populated areas, potentially disrupting natural habitats and wildlife, particularly in U.S. national parks. While outdoor lighting enhances safety and navigation, researchers emphasize the need for a balance to mitigate its harmful effects on ecosystems and wildlife, suggesting that excessive artificial light can have far-reaching consequences for both human health and environmental integrity.