Insects are the world’s most numerous and diverse animals. Even where you’d least expect them in some of Earth’s most extreme environments, there they are. From a scalding volcano, parched desert, to a frigid glacier, insects are living life on the edge. So, how do they do it? Charles Wallace illuminates the incredible survival skills of insects living in some of Earth's harshest ecosystems. Lesson by Charles Wallace, directed by Raghav Arumugam, Jagriti Khirwar.