Insect ethics: the painful truth?

It seems that the list of creatures that we used to think could not experience pain is shrinking again:

Study argues insects feel pain, raises questions around ethical farming


The question of whether or not an organism feels “pain” is, to my mind, a red herring.

Every living organism must respond to its environment, and there is necessarily a higher priority placed on environmental stimulus that indicates immediate harm. As a result pretty much all organisms react to harmful (eg. ‘painful’) stimulus in a manner that cannot reasonably be separated from a pain response, even if said organism lacks pain receptors (nociceptors). This holds true for all animals, including arthropods, as well as plants and microorganisms.

Several big problems are that historically the experience of pain has been linked with consciousness (which is part of why there has been a resistance to admitting that other creatures experience something akin to pain) and that we lack the necessary knowledge and vocabulary to assess exactly what and how pain-like responses work in other organisms.

Baluška has argued that plants feel something akin to what we call ‘pain’ despite lacking the receptors and neural architecture that makes the experience possible in animals, and others have pushed back on that idea. The Draguhn, et al 2021 paper Anesthetics and plants: no pain, no brain, and therefore no consciousness covers this debate well.

I think that both sides of this miss the mark, as do questions of where the ethical line lies.

Living things eat each other, and the concept of ethics is a human construct (albeit one that has a decently widespread foundation in mammals, especially vis-a-vis “fair play” and equitability as the work of Frans de Waal and others indicate).

Rather than debating where the ethical ‘line’ is, we should be treating all organisms with respect. That doesn’t mean we don’t eat them, or don’t prune plants, or don’t kill mosquitoes, but it does mean that we should avoid doing intentional harm to other organisms as much as possible, no matter where they rest on the tree of life.


Well said, I used to have this discussion with my neighbor whose husband was a “scientist”. You put it so well compared my own arguments.


My graduate work was in neuroscience, specifically neuropathic pain. We actually had to be very careful in our language, because pain is actually a multifaceted complex thing that even scientists don’t fully understand (we all experience it differently, despite same biology!); we can only say (for example) the rats in the study which have nociceptors - experience nociception but we never used the word pain. Pain itself, scientifically, is " a complex experience consisting of a physiological and a psychological response to a noxious stimulus". Since we cannot know what goes on in the psychology of (in our example) rats, only the physiological response, it is nociception, not pain.

Now…I’m not going to say rats don’t experience pain. I just can’t say they do. This is a fine but important distinction. And there are clearly ways to respond to stimuli that would cause harm that is not recognizable as nociception due to lack of nociceptors. But: Point being: Scientifically - even nociception =/= pain. It may be a ‘safe assumption’, but it isn’t actually provable.

That said, in the end, yes. Just treat all organisms with respect. Just because we cannot communicate well, don’t know their intricate biologist or how they think/reason (which goes far beyond pure behavior that we can observe), so avoid harm wherever possible. But hate to break it, living on this earth you are at some point going to harm something, cause you are part of a ecosystem!


Since it is not ethical to inflict physical harm to those poor people who cannot perceive pain, the question might be wether the ability to feel pain qualifies as justification for harming a living thing in the first place.


Agreed. A world without pain would be, at least* on the animal front, a sterile world. It’s a primal sense of being alive. As is the harming of other living things.

  • Becoming more debatable! Plant perceptions of their environments and how they communicate with each other. Hot topic.
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When I bump my leg or arm on something I will go ‘ow’ reflexively, but there is no pain associated with that ‘injury’. I suspect that this is what many invertebrate species do. Their behaviour resembles pain, but is not, in the sense that humans know.
About 6 months ago, I slipped on some ice, and damaged my elbow. It still hurts today, but nowhere near as much as then. But only in specific situations. I know there is nothing physically wrong, so mentally dismiss it. It’s a trite (and dismissive) expression, but pain is all in your mind. I’ve been physically hurt a lot, so have some experience! Emotional pain is a different thing.
Having said that, I suspect there are few reasons why humans would want to kill or inflict any discomfort on non-human life unless there was a very good reason to do so.

This is because nociceptors are actually friggin slow.
I mean it seems fast, but it isn’t, compared to reflexes (which don’t always even need to get to our brain to happen - CNS includes spine ;) ), or actually most other sensory input. Nociceptors are essentially the slowest of all our sensory pathways. This is why when you stub your toe, you retract and say ‘ow’ before you even notice if there is pain or not. Notice you still retract and say ‘ow’ before you feel the pain a lot of time, even when there is pain! Your brain literally processes from history + the mechanical sensation that this should hurt, before you know if it actually hurt!

Fun trick with nerves: some mechanoreceptors are linked with temperature, so take a really fine pencil (0.3 or 0.5 mechanical or such), and gently touch the backside of your hand pressing lightly, move to a new spot after about a second if you don’t feel anything odd; you’ll know when you find it, you’ll feel a localized sensation of cold all of a sudden. One of our fav “try this!” tricks :) Usually at this same point if you press harder, the cold will turn painful (not horribly so, in the ‘holy crap this is weird and cool’ way). temperature and nociception are processed somewhat similarly (very oversimplifying but anyway). And now i’m done with my tangent


This may seen too unscientific for some of you, but my view is that the more like us an organism is, the more like ours its experiences are. Is there a logical reason why the psyche shouldn’t be as subject to phylogeny as are the morphology and physiology?


That’s not a safe assumption. If you’re still getting periodic pain from it, that indicates that something is wrong with it. It may be something minor, but it may also be something more.

A while back I slipped on algae when parking my bike. Went down and bashed my knee. A year and a half later it usually feels fine, but certain positions and even a light tough in the right way hurts immensely, because I damaged some of the sacks that contain the protective fluids for the knee. It may get better on its own, or it may get worse.

Seeming small, intermittent pains that persist are sometimes an indication that the damage was greater than you thought and that it’s not getting better.

Don’t make the assumption that nothing is wrong, pay attention to it rather than dismissing it, and track how it feels over time.


That’s one of the best explanations of nociception I’ve heard, and I used to be an ICU nurse!
I will try that trick. Sounds fun!


awe thank you :) i was lucky in grad school to have some excellent training in scientific communication just because of one professor being really good at it, so i try very hard to use it!

I do agree I wouldn’t dismiss pain in your elbow though; people really underestimate how long it takes soft tissue to heal, or what if a bone chip, or such, occurred. Could also be something like bursitis which seems to take docs foooorever to Dx but is common for joints like knees and elbows.


You need a better understanding of chronic pain.

Can you elaborate? I know there’s phantom pain, which really throws a wrench into simple ideas of physical pain, for example.

Yes insects feel pain when it is injuried, can see it is writhing. If we imagine that, we feel pain too. Human beings is said to have abstract thinking capability. This distinguishes our species from all others on earth, with possibly a few other exceptions.
Many insects evolved to take advantage of a sudden abundance of resources available to them. They have a fast reproduction rate, and are the bottom of the food chain. They are food of birds, they help decompose the poop of other creatures, dead fishes on the beaches. They are spreaders of vector diseases, take a cut from our crops. Some are human’s nemesis.
Insect farming ? There may a trend of black soldier fly farming, able to reduce food waste of cities. Cockroach farming done on a massive scale. Cricket farming is noisy. It is used for feeding pets, fishes.
Tissue culture technology is on the way. Meat-like products without the animals having “a bad day in life” . I’m not willing to be a guinea pig to test these stuff.

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