I am open to exploring ways of increasing and decreasing the population of wild invertebrates. I guess the probability of these having positive/negative lives is roughly 50 %.

To be honest, I’m surprised you’re giving them a 50% chance of a net-positive life while equating one second of 'excruciating pain' to 24 hours of 'healthy life.' While that distinction might have seemed minor in our previous discussion, it’s of paramount importance here.

Pain perception is highly subjective and, more importantly, something one can adapt to. Consider someone with no experience in sports: getting tapped by a stray volleyball on a schoolyard might feel like a major ordeal. Meanwhile, a goalkeeper taking a 100km/h shot to the face will insist it was a great experience because they made the save. Even they might look soft compared to a Thai boxer, who will literally laugh in their opponent's face after taking a heavy hit.

Now guess who does crazy Thai boxer look up to? Wild animals. They are tough as nail as Marc Bekoff puts it in his masterpiece Wild Justice. If we must anthropomorphize, we should at least use empirical data from people who are actually accustomed to pain. Judging the lives of wild animals by the standards of academics used to a sedentary lifestyle is arguably the biggest mistake we could make.

Furthermore, we should always err on the side of caution. If we are designing a vaccination program, assuming the disease is devastating to them because it would be devastiting to us is a reasonable baseline. But if we are contemplating something as extreme as zoocide, we had better be absolutely certain that their lives aren't worth living by their standards, not ours.

Thank you for sharing the link. I completely agree that MichaelPlant articulated this position far better than I did, and I highly recommend reading his post. I suspect mine gained so much traction not necessarily because of its quality, but because the issue itself is of paramount importance. Getting these things right is crucial, even if it often feels like an impossible task.

Thank you for pointing this out. I deliberately chose a single animal for the thought experiment because I didn't want to argue that I know whether suffering makes up a large part of their lives, but rather that no one can know. That notwithstanding, apparently there are people out there who are contemplating killing billions of invertebrates for their own supposed benefit.

Thank you for your kind words. I couldn't agree more with your reasoning.

Thank you for the kind words. I feel you brought some very important arguments to the discussion as well.

There seems to be vague agreement that predators probably have net positive lives, but herbivores, insects, and r-selected species have net negative lives. This seems incorrect to me, or at least counterintuitive.

Are you talking about the few people in the EA community working on this issue, or also people outside the community? I have never actually encountered anyone holding this view in person, despite attending various animal advocacy conferences.  In fact everyone I've told about this concept seems genuinely appalled by it.

That might be a cultural thing. I'm from Austria, and the concept of lives not worth living was one of the justifications Nazis used to kill human beings.

I'm glad Bob holds this view and I didn't want to single him out negatively. In fact I think his work is tremendously important. I especially appreciated the animal welfare table he co-authored, and in the same database there are interventions actually aimed at saving animals, like number 5: "Climate-friendly technologies and invertebrate mortality."

I still find it alarming that the research question in this particular case was something along the lines of "Can we assist in bringing invertebrate numbers down by accelerating subsidies?" instead of "Can we save lives by opposing these subsidies?"

I totally agree that research should be a main focus. It stops being effective altruism when one part of the community puts their effort into saving invertebrates while another part wants to kill those same animals.

"I think the priority should be decreasing the uncertainty about effects on soil invertebrates (for example, determining which have positive or negative lives for each biome)" 

What would actually convince you that a certain species lives a "net negative life"? Or that it lives a particular good life?

I agree that both positions carry real risks. Classical utilitarian concepts like "net positive" or "net negative" lives don't seem very helpful here. We simply don't have the data to make even an educated guess, let alone a proper calculation.

There are several frameworks that might serve us better: preference utilitarianism, for one: insects clearly exhibit a preference to live. Or the "do no harm" principle. Or basic moral intuition: killing healthy individuals is not normally considered a way of helping them. And then there's the precautionary principle: driving species to extinction is irreversible, and it is virtually impossible to reduce insect populations at scale without doing exactly that.

I don't think arguing for net negative lives should be taboo quite the contrary. As I argued in my original post, speculative ideas have value, as long as they are presented as such. My concern is that some proponents of this view have moved beyond speculation and are now acting on it as if it was an established theory.

One example: on March 25, Bob Fischer and Rethink Priorities published a database of near-term interventions for wild animal welfare. Entry number three: "Biofuel subsidies as a mechanism for reducing invertebrate populations" uses the word reducing as a euphemism for killing insects through pesticides and habitat destruction. To be fair, the authors concluded that the EA community is not well-placed to intervene here. But the fact that they considered ways to accelerate such subsidies rather than oppose them suggests they view killing these animals as a good thing.

Should this view be silenced? No. They have freedom of speech, just as I do. But it's our job to push back. Good intentions don't earn anyone a free pass. A bug doesn't care whether it's killed for profit or for its own supposed benefit. The road to hell is paved with good intentions.

A predator would have known what to do and that is actually one reason I consider predation among the more merciful ways to die, provided you are not unlucky enough to be caught by a cat with time on its hands. Predators kill quickly. Insecticides and disease rarely do.

Having that said, I think you made the right call. Insects appear to be remarkably insensitive to mechanical injury, at least in any prolonged sense. They do not regrow limbs, but they do seal wounds efficiently and carry on. Feeling persistent pain in response to physical damage would arguably be maladaptive - and they give us little reason to believe they do. A rough human analogy might be internal injuries serious enough to be fatal, yet never consciously registered at all. Insects do, however, appear sensitive to heat and electric shocks - precisely the conditions they are subjected to during the killing process in insect farming.

There is also good evidence that insects experience something resembling mood. A well-known study found that agitated bees display negative cognitive biases. Responding to ambiguous stimuli as though expecting the worst in ways that parallel what we might cautiously call a pessimistic state. The original paper even used the word depression.  Conversely, bees finding food appear to shift into something like a positive mood. So perhaps your bug was not in pain when it limped away — but if the research on bees is anything to go by, losing a leg is exactly the kind of thing that might tip an insect into a genuinely miserable state.

None of this settles the question of whether insects lead net positive or net negative lives. But the evidence cuts both ways. Their apparent insensitivity to mechanical injury might just as easily indicate that their lives are, moment to moment, quite good - unburdened by the anticipatory dread and chronic pain that weigh so heavily on human experience. The lives of honeybees, at least under natural conditions, seem rather enviable by any reasonable measure.

I couldn't agree more. I'm vegan for only 6 years now and already convinced several people to go either vegetarian, almost vegan or reduce their meat consumption. (No total victory yet, unfortunately) It also enabled me to have literally hundreds of deep talks about animal suffering. People listen to people who are close to them. You are in an unique postion to influence your very own social circle and you shouldn't let it pass if you are truly commited in doing the most good. 

I totally agree with your conclusion. I like to read your posts and I'm sorry for derailing this one. I was just genuinly surprised anyone would assume that one single second of any pain could be "as bad as losing 24 h of fully healthy life."