For all the admirable efforts to solve the world’s problems – beating malaria, improving education access, closing the digital divide – one simple need tends to fall by the wayside: We humans have to poop, and some 2.5 billion of us don’t have the proper facilities to do so. Think about what that means for a second: Beyond the commodes themselves, roughly a third of the planet’s population lacks sanitation, leaving communities susceptible to disease and filth.