Building things with robots is a nice idea, especially if robots are doing what they’re best at: predictable, repetitive tasks like you get with bricklaying. When humans build structures, however, we can be a bit more creative, adapting on the fly to the sizes and shapes of materials available. This is one of those robotic paradoxes—building something that’s easy for robots, like an exactly spaced curvy brick wall, is tricky for humans, while building something that’s easy for humans, like a wall made out of pile of random rocks that doesn’t spontaneously fall over, is tricky for robots.