As previously mentioned, rudimentary cloning technology derived from vitanoform and fleshvat lore of the ancients is still used by the Adeptus Mechanicus, yet it would be horrendously inefficient for the tech-priests not to also make use of the biological machinery of the operational human production units themselves. Waste not, want not. It is best to maximize input from a wide variety of sources, including vat-grown cloning of bodies, offworld press-ganging of slave labour, and natural human breeding. The latter, however, is usually rigorously controlled by artificial means and systematized into an ordered grid of rigid production schedules to better meet expected human wastage levels and future demand for labouring flesh. Only seldom will local sects of the Adeptus Mechanicus allow independent primal rutting to freely dictate the rhythm of body input into their monstrous calculations.

Unlike the Imperium proper of Holy Terra, the empire of the Adeptus Mechanicus do not believe in family. This primal organic unit is messy, unsystematized and disorganized, akin to a pigsty. Instead of parents and siblings, children on forge worlds and millholms will often grow up in a ladder of dismal institutions, where their age or evaluated productivity level dictates which rung in the ladder they find themselves in. The lowest rung of these functional orphanages will take care of infants who are usually given all the necessary nutrition, sleep and temperature regulation by lobotomized servitors, and yet still some babies wither away and die from lack of human contact, love and attention. Clearly, such weaklings were not fit for the rigours of life in the first place.

This neglect only intensifies as the toddlers are moved up into institutionalized units for the instruction and cultivation of small children. Instead of warmth and care, these liberi will be subjugated to ceaseless indoctrination, in order to better prepare them for their ordained roles within the Cult Mechanicus. Their first cerebral implants will be installed, the better to allow transfer of information directly into the children's skulls and waste as little time and resources as possible on mundane teaching. This short education will mainly deal with religious instruction fit for the most basic castes of the Machine Cult, as well as all manner of practical tech knowledge and the ability to read, write and calculate, to prepare the children for an early labour start on the floors of manufactoria and shipyards. The most promising pupils will be inducted into more prestigious institutions to prepare them for induction into the mysterious orders of the tech-clergy, where they will rub shoulders with the prodigious fruits of selective breeding and eugenics.

In order to foster a hardy spirit, supervisors will cultivate violence and fear in order to humiliate and control the children through draconic punishment. Electrical shocks and pain-inducing alchemical concoctions will be administered in full view of everyone else to misbehaving human progeny. Likewise, children found quarrelling will often be ordered to hit or taze each other as part of their disciplinary penalty, thus undermining any forming of close bonds between peers that might act contrary to subservience to the Cult Mechanicus. Older kids will usually steal away opportunities to hit and kick smaller ones, often as an outlet for their own frustrations and repressed aggression, thereby cultivating a virtuous cycle of violence against those younger than themselves. Thus the spawn of man is taught to be ruthless and to hate from an early age. To further promote the overbearing sense of isolation and mechanistic, inevitable cruelty, novitiates, federii and liberi will never be notified in advance when they are to be moved from one institution to another section, for they will be moved around like boxes, without personal belongings and without any chance to say goodbye to anybody they might have known. Inter-human attachments must not be formed, for that way the feebleness of flesh lies over yonder.

The entire environment of upbringing within the juvenile institutions of the Adeptus Mechanicus amounts to children being wiped out as human beings, their voices silenced, their weak selves humiliated, their wills broken. Only by dissolving the personalities of tender humans in such slaughterhouses of souls can a new and better man be built, one filled with zealous adherence to the Credo Omnissiah and one capable of becoming as one with the machine, both in body and mind. What use do children have for their mothers and fathers? What use do plebeians have for knowing their relatives? All relevant data are as a rule mapped out in genealogical pedigrees of controlled breeding, available only to the concerned blessed experts who can enter the correct clearance codes. This cold and mechanical treatment of human youngsters contributes greatly to moulding the subjects of the Cult Mechanicus into faceless numbers in enormous masses of replacable human machine components.

Weak-willed outsiders might find this arrangement to be joyless, resulting in a life bereft of tender contact and human warmth. Mayhap it will even result in raising generations upon generations lacking the finer things in life altogether. Such nonsense is not even worth the dignity of dismissive answer. No, listen not to the white noise of infidels and barbarian ignoramii. Let there be an unsentimental harvest and planting of seed, for the flesh is weak. We must strive to become one with the machine, act the machine, be the machine, even if scraps of flesh and organs still cling to our forms. The machine moves in patterns of mathematical exactitude and purposeful repetition, and so should we do as well in matters of the flesh.

Get rid of your delusions of the flesh, for they will lead you astray from the deeper reality hidden beneath the dull exterior that your unreceptive optic organs perceive in their state of half-blindness, ignorant as your ocular organs are to pure expressions of true reality such as observable heat differences and the spectrum of light. Shun illogical thought of self, for how could a wheel revolt against the axle around which it rotates? Purge irrational vanity, for how could a transmission belt care for its appearance? Form is but a manifestation of function, and there is no other beauty in all of creation than sacred function, just as there is no higher mystery outside the sacred reach of pure, unadulterated knowledge.

Thus man on thousands of forge worlds and innumerable vassal voidholms will be produced on an industrial scale, akin to machines making other machines. A higher system of reproductive engineering has replaced untamed patterns of feral copulation. The purity of cold calculation has replaced the abominable fragility of emotion, and so humans are extracted of their seed and impregnated routinely like one would inseminate domesticated grox and other cattle in agriculture. When speaking of this process, we must naturally exclude those human production units who have been chem-gelded, organ-crushed or otherwise rendered sterile and barren. Such impotent conditions may usually come about either in all-too common industrial accidents, or as a normal genetic hygiene punishment for repeated work failures that attract the judging eyes of superiors (although servitorization is a far more common measure), in order to not promote the passing on of undesirable traits to future generations of menials. For if the machine pool of a facility is to be cleaned and maintained with regularity, then surely the labour pool servicing the machines must be likewise cleaned and maintained without failure?

And so the servants of Mars and all its daughter holdings are created in coordinated breeding programs, where inception, gestation and delivery performs like oiled clockwork. On some forge worlds and voidholms of the Adeptus Mechanicus, this entire procedure is mechanically automatized into something resembling a rolling assembly line with strapped human bodies being processed at high speed, while at other places a simple queue to a large facility for mass extraction or injection will suffice. Know that the need for comfort is a false craving of the flesh. Rank within the Cult Mechanicus will determine the insemination process. Among both males and females, lowly menials and lay tech-folk will routinely have their arms and legs locked to a moveable hard table during the mechanical procedure in order to forestall any time-inefficient thrashing about of potential unwilling slaves, while Cult members inducted into the tech-priesthood and its arcane mysteries will be expected to fully understand the order of things and thus comply piously without any need for restraints.

As to the human produce of such scheduled factory programs, the small bodies of children make for poor labourers, while their young brains make for simple servitors. Although there are many tasks that are lightweight and menial enough to entrust to a child, such little work do not invite much else than dismissive views from the Adeptus Mechanicus. After all, the desired end product is a fully grown human production unit, whereas childhood stands as nothing but a time-consuming obstacle to the labour replenishment process.

Thus crops of despised and inefficient children will often be injected with variably volatile growth stimulants to accelerate their maturation into peak fitness juves and adults of far better efficiency levels than childishly undeveloped offspring possess. Still, children and tender juves can be put to reasonably heavy work and run errands for adult labourers. And so children can be seen scrabbling about inside great machines, where they pick cotton in textile factorum cathedrals, their work rhythm set to the precarious pulse and sudden thrusts of raking machinery that they must nimbly avoid at their own peril. Such utterly dangerous child labour is all beneficial to the running of the Great Machine, and thus it must never be shied away from. And as man in the far future has come to replace more and more machine tasks with manual labour, the industrial uses for children have slowly grown in number over the fivehundred generations that make up the Age of Imperium. For instance, the small bodies of liberi are well suited to claustrophobic labour tasks such as minor chimney sweeping, cleaning out nooks and cranies of lethally active machines in operation, and the horrible drudgery and crawling to cleanse pipes and large hoses from the inside, in which case bestial pipe lurkers are sometimes lying in wait for an easy prey to slowly devour alive, out of sight, out of mind. And so the pipe-cleaning kid may themself end up clogging the arteries of manufactoria.