In Ned Beauman's 2023 novel Venomous Lumpsucker, the protagonist happens upon a breeding experiment in the open sea: a self-sustaining system designed to continually output an enormous number of blissfully happy insects, yayflies.
The yayflies, as he called them, were based on Nervijuncta nigricoxa, a type of gall gnat, but... he'd made a number of changes to their lifecycle. The yayflies were all female, and they reproduced asexually, meaning they were clones of each other. A yayfly egg would hatch into a larva, and the larva would feed greedily on kelp for several days. Once her belly was full, she would settle down to pupate. Later, bursting from her cocoon, the adult yayfly would already be pregnant with hundreds of eggs. She would lay these eggs, and the cycle would begin anew. But the adult yayfly still had another few hours to live. She couldn't feed; indeed, she had no mouthparts, no alimentary canal. All she could do was fly toward the horizon, feeling an unimaginably intense joy.
The boldest modifications... were to their neural architecture. A yayfly not only had excessive numbers of receptors for so-called pleasure chemicals, but also excessive numbers of neurons synthesizing them; like a duck leg simmering luxuriantly in its own fat, the whole brain was simultaneously gushing these neurotransmitters and soaking them up, from the moment it left the cocoon. A yayfly didn't have the ability to search for food or avoid predators or do almost any of the other things that Nervijuncta nigrocoxa could do; all of these functions had been edited out to free up space. She was, in the most literal sense, a dedicated hedonist, the minimum viable platform for rapture that could also take care of its own disposal. There was no way for a human being to understand quite what it was like to be a yayfly, but Lodewijk's aim had been to evoke the experience of a first-time drug user taking a heroic dose of MDMA, the kind of dose that would leave you with irreparable brain damage. And the yayflies were suffering brain damage, in the sense that after a few hours their little brains would be used-up husks; neurochemically speaking, the machine was imbalanced and unsound. But by then the yayflies would already be dead. They would never get as far as comedown.
You could argue, if you wanted, that a human orgasm was a more profound output of pleasure than even the most consuming gnat bliss, since a human brain was so much bigger than a gnat brain. But what if tens of thousands of these yayflies were born every second, billions every day? That would be a bigger contribution to the sum total of wellbeing in the universe than any conceivable humanitarian intervention. And it could go on indefinitely, an unending anti-disaster (p. 209-210).
Now suppose classical utilitarian ethics is correct and that yayflies are, as stipulated, both conscious and extremely happy. Then producing huge numbers of them would be a greater ethical achievement than anything our society could realistically do to improve the condition of ordinary humans. This requires insect sentience, of course, but that's increasingly a mainstream scientific position.
And if consciousness is possible in computers, we can skip the biology entirely, as one of Bauman's characters notes several pages later:
"Anyway, if you want purity, why does this have to be so messy? Just model a yayfly consciousness on a computer. But change one of the variables. Jack up the intensity of the pleasure by a trillion trillion trillion trillion. After that, you can pop an Inzidernil and relax. You've offset all the suffering in the world since the beginning of time" (p. 225).
Congratulations: You've made hedonium! You've fulfilled the dream of "Eric" in my 2013 story with R. Scott Bakker, Reinstalling Eden. By utilitarian consequentialist standards, you outshine every saint in history by orders of magnitude.
Philosopher Jeff Sebo calls this the rebugnant conclusion (punning on Derek Parfit's repugnant conclusion). If utilitarian consequentialism is right, it appears ethically preferable to create quadrillions of happy insects than billions of happy people.
Sebo seems ambivalent about this. He admits it's strange. However, he notes, "Ultimately, the more we accept how large and varied the moral community is, the stranger morality will become" (p. 262). Relievingly, Sebo argues, the short term implications are less radical: Keeping humans around, at least for a while, is probably a necessary first step toward maximizing insect happiness, since insects in the wild, without human help, probably suffer immensely in the aggregate due to their high infant mortality.
Even if insects (or computers) probably aren't sentient, the conclusion follows under standard expected value reasoning. Suppose you assign just a 0.1% chance to yayfly sentience. Suppose also that if they are sentient, the average yayfly experiences in its few hours one millionth the pleasure of the average human over a lifetime. Suppose further that a hundred million yayflies can be generated every day in a self-sustaining kelp-to-yayfly insectarium for the same resource cost as sustaining a single human for a day. (At a thousandth of a gram per fly, a hundred million yayflies would be the same total mass as a single hundred kilogram human.) Suppose finally that humans live for a hundred thousand days (rounding up to keep our numbers simple).
Then:
If prioritizing yayflies over humans seems like the wrong conclusion, I invite you to consider the possibility that classical utilitarianism is mistaken. Of course, you might have believed that anyway.
(For a similar argument that explores possible rebuttals, see my Black Hole Objection to utilitarianism.)
[the cover of Venomous Lumpsucker]