If you have any interest in sci-fi you’re bound to have come across nanobots at some point: swarms of tiny machines that are invisible individually but come together in huge clouds to take on the shape of various objects or people. Sci-fi has predicted them for decades, and science edges closer and closer to catching up…but nature got there a long time ago. Inside our bodies are motors, pumps, springs, and levers made of just a handful of atoms. There are things that walk, climb, and swim around our bodies building and maintaining them. These are dwarfed by the huge factories that create them: the 10000000000000 or so cells in the average human body. We are the original nanobots.