Terrestrial arthropods (insects, spiders, etc.) dominate the world in numbers and extreme diversity. This book presents the combined views of a physicist, a chemist, and a biologist on the fascinating interactions of these organisms with the primary source of energy on Earth, light. It describes the plethora of important phenomena observed in different spectral ranges, from ultraviolet to visible to mid-infrared. These phenomena, often unprecedented, occur at all scales - macroscopic, micr...