At a glance, a single worker of the genus Macrotermes is not a very complex creature—less than half an inch long, eyeless, wingless, with an abdomen so transparent you can spot the dead grass it ate for lunch. Put it in a group, though, and it may pile up pinhead-sized balls of mud, one after the other, until a complex mound takes shape. By the time that mound is 17 feet tall, it will be equivalent in scale to the Burj Khalifa.