| Why isn't the world covered in poop? Lesson by Eleanor Slade and Paul Manning, animation by Anton Bogaty Each day, the animal kingdom produces roughly enough poop to match the volume of water pouring over Victoria Falls. So why isn’t the planet covered in the stuff? You can thank the humble dung beetle for eating up the excess. Eleanor Slade and Paul Manning explain how these valiant insects make quick work of an endless stream of feces. View full lesson » | | | A day in the life of a Roman soldier Lesson by Robert Garland, animation by Brett Underhill The year is 15 CE, and the Roman Empire is prospering. Most of the credit will go to the emperor, but this success wouldn’t have been possible without loyal soldiers like Servius Felix. Robert Garland illuminates what life was like for a solider in the Roman army. View full lesson » | | Constantly Curious on Facebook Watch | | | Why do we feel nostalgia? Lesson by Clay Routledge, animation by Anton Bogaty Nostalgia was once considered an illness confined to specific groups of people. Today, people all over the world report experiencing and enjoying nostalgia. But how does nostalgia work? And is it healthy? Clay Routledge details the way our understanding of nostalgia has changed since the term was first coined in the late 17th century. View full lesson and follow Constantly Curious on Facebook Watch » | | |