In the hostile environment of the Central Desert, insects have found a way to create their own living conditions. Here and there on the exposed surface, jagged, dusty towers rise up out of the sand, jutting many feet into the air. At the pinnacle of each structure there are translucent panels that could almost be windows. These towers are the cities of terabytes.
Like any termite, terabytes are eusocial, which means they form a colony in which a single queen breeds while every other individual performs distinct tasks essential to the colony's survival. In colonies like these, individuals are divided into several castes, each with a function of its own.
The fiercest terabytes are those in the warrior caste. Their disproportionally large heads generate chemicals which they squirt from nozzles to fight enemies and secure targets. Insects have long been equipped with chemical weapons produced within their own bodies. An ant bite can deliver a potent dose of formic acid. Termites have always squirted noxious chemicals at intruders. 200 million AD, such systems have developed to a high degree of sophistication.
The sandy citadels of the Central Desert are constructed by the builder caste of terabytes. They gather sand grains, along with the carcasses of their comrades and their own feces, and cement the particles with a natural secretion produced in their internal chemical factories.
Terabyte rock-borers (similar in appearance to warriors) produce acid which they use to burrow down through the limestone rock, carving out tunnels, shafts and chambers to reach the reservoirs of water deep below - aided by the biter caste, which have strong jaws. Members of the water carrier caste bloat themselves by drinking the water and saturating their tissues, then they redistribute it throughout the colony.
Most remarkably, all but one of the terabyte castes are, quite literally, legless. Each individual has a head, a body, feeding organs and organs to generate and secrete chemicals, but it cannot move unless it is carried. Terabyte haulage is carried out by a transporter caste whose members seem to be nothing but legs. Their sole function is to carry other terabytes on their backs, relocating them as they are needed.
Every day the transporter caste carries all other castes into the greenhouse to feed. Members of a nurse caste scrape up quantities of algae and are carried deep into the colony, where they feed it to the queen. Minute after minute, hour after hour, the queen produces eggs. She must produce offspring constantly to maintain high enough levels of population for the colony to survive.The terabyte towers are merely the tips of the colonies. A network of tunnels and shafts, hundreds of feet deep, extends the structure into the rock below and forms the largest part of the nest. Daylight slants into their cavernous interiors through transparent windows, spun from a clear polymer by the builder caste. Heat generated by the sunlight evaporates water at the base of the structure and cools the atmosphere in the tower. This generates a convection effect, circulating carbon dioxide-rich air throughout the structure. Sunlight and carbon dioxide produce ideal conditions for the growth of plants and algae. The exposed part of the terabytes' nest is actually a carefully engineered greenhouse.
Long ago, before the desert conditions became so harsh, the terabytes' ancestors fed on algae that fed on the muddy puddles of scattered oases. As the desert became more hostile, the oases vanished and aquifers, layers of water-bearing rock, sunk further below the surface. The algae would have died out in the desert had it not been for the insects bringing them to the surface to allow them to photosynthesize.
Now, the terabytes of the Central Desert have evolved a sophisticated system of cultivation. Inside each terabyte tower is a complex network of internal scaffolding, built from the same cemented particles as the rest of the structure. The planes and surfaces of this scaffolding are angled towards the light shining in through the organic windows. Algae coat the surfaces, clinging in thick mats and hanging in streamers. Energy from the sunlight combines with carbon dioxide and water vapor to produce an algal food supply which nourishes the entire colony. The tip of the terabyte mound is not so much a dwelling place as a farm, designed for the photosynthesis of the algae.
Throughout this complex social structure there seems to be a single, corporate intelligence that understands the requirements of the whole colony. The colony functions as though it were a single organism, its whole truly greater than the sum of its parts.
From time to time, the terabyte farmers must renew their stocks of algae, no easy task when algae (and even vegetation) is scarce. Terabytes solve this problem by removing the algae from the tissue of another animal: garden worms.
Parties of terabyte warriors, carried by transporters, will seek out a basking garden worm. They will swarm over the rocks, the warriors firing sticky threads from the chemical nozzles on their heads, gluing an unwary worm to a rock or the ground. Transporters will begin to cut away at the immobilized bristle worm's algal tissues. The garden worm will fight back. It will issue a secretion that dissolves the glue. The bonds weaken and tear and soon the worm is free (minus a few algae). The battle will be over, but the terabytes have been able to tear off enough alga-rich tissue to restock their greenhouses.
- The terabyte nest-building skills/caste system was probably inspired from the meaching from After Man: A Zoology of the Future, the gestalt from The New Dinosaurs: An Alternative Evolution and the communal plains-dweller from Man After Man: An Anthropology of the Future.
- "Terabyte" is also used in computer terms for one one million bytes.