She builds a sealed clay vessel with nothing but mandibles, saliva and mud, then hangs her only offspring from the ceiling of it by a thread. The female potter wasp (subfamily Eumeninae) is a solitary architect. No colony, no workers, no division of labour. One female performs every task in the reproductive cycle, and she performs it in a strict sequence that cannot be reordered without killing the brood. The build begins with water. She regurgitates it onto dry soil, works the slurry into a pellet roughly the size of a peppercorn, and flies it home in her jaws. Each pellet is laid as a ring and consolidated by high-frequency vibration of the mandibles, which liquefies the mixture briefly so it flows into the previous course before setting. The result is a wall often under a millimetre thick, hard enough to resist rain, with a flared neck that would look at home on a potter’s wheel. Then the sequence that makes her remarkable: - She lays the egg into an empty pot, suspended from th...