While humans are the brawn of Aekallia, nanos (homo diminutus) are the brains.  This is a natural consequence of being the staple food of the planet - much of a nano's life is spent in the stomachs of  predators.  Some of the earliest nano inventions include the reading light, belly-pack, and waterproof book, and university classes are often held in the belly of a beast.  Although there are some revolutionaries preaching nano rights and "freedom from ingestion," most have learned to accept and even enjoy their fate as food.  Indeed, a great many make a living earning commissions  as food in human restaurants.