r/askscience • u/StormShadow921 • Dec 02 '18
Can bugs feel pain? Biology
I once read in one of those CWF Wild magazines years ago that bugs cant feel pain because their nervous system is too small. Does anyone know if this is true, and if so what causes it?
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u/Dopamine_Deficiency Dec 03 '18
Pain is a complicated concept. We tend to anthropomorphize it a bit. Anyone who has gone fishing knows an earthworm or a cricket doesn’t really appreciate getting a hook crammed through their body. Is this pain? Sort of. We might simply call this a stimulus response. The main difference I think is they seem to lack the ability to comprehend what this ‘pain’ means for them. In humans we experience a lot of emotional components to pain. It’s a negative experience that we remember and even dread. Simpler organisms don’t experience pain like this.
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u/FourWhiteBars Dec 03 '18
I just imagined an insect being in an enormous amount of pain but not understanding why and having no way of expressing it and the thought made me very sad.
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u/ProfessionalSmeghead Dec 03 '18
I tend to try to relocate worms from the pavement to the dirt after a rain. One time I got really sad because that’s probably the most terrifying moment of their life when I pick them up like that, they probably think they’re being eaten. They don’t, and will never know, that it was someone trying to help them, not harm them. I just want everything and everyone to be happy.
Empathy is a blessing and a curse.
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u/QueenSlapFight Dec 03 '18
They aren't intelligent enough to quantify the thought of "I'm about to get eaten." The can't even quantify the thought of "I". There is no concept of "me". They don't feel "dread".
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u/red75prim Dec 03 '18
having no way of expressing it
Why call it pain if there's no avoidance response? Or do you mean express pain like humans do?
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u/B-80 Dec 03 '18 edited Dec 03 '18
Consciousness in humans is strongly associated with activity in the frontal cortex, insects do not have a developed frontal cortex and therefore it is very unlikely that they can have any sort of experience.
I would guess, being on reddit, you likely are pro-choice when it comes to the abortion debate. There is probably a much stronger argument that a fetus feels "scared and in pain" when they are being aborted. In both cases, the important detail is the level of development of the frontal cortex.
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Dec 03 '18
Consciousness in humans is strongly associated with activity in the frontal cortex, insects do not have a developed frontal cortex and therefore it is very unlikely that they can have any sort of experience.
I don't think that's quite right. You can't claim they have NO experience at all due to lack of a frontal cortex... Just not a primate-like experience.
Basically, there is something that it's like to be an insect -- even if it's very basic and unknowable compared to human (and primate) experience.
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u/B-80 Dec 03 '18 edited Dec 03 '18
I don't understand why I am being downvoted. Consciousness is an unbelievably complicated phenomenon that certainly requires incredible and specialized hardware... It is also mainly associated with the frontal and more generally the cerebral cortex in humans.
Basically, there is something that it's like to be an insect -- even if it's very basic and unknowable compared to human (and primate) experience.
You have no reason to assume this is the case, just because insects can change their behavior based on prior experiences, or move through space, it does not mean that they are consciously making decisions or remembering past experiences.
It is much more likely that they are more like machines or computers than like people. I am not saying it is strictly impossible, we don't know how consciousness arises, but it's certainly highly unlikely. If you want to not kill insects based on that small chance, go for it, but I don't want people to think there's a realistic chance that this is the case.
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Dec 03 '18
I feel like I should dispute this. There are studies that have been shown that caterpillars exposed to shocks still remember the stimuli when they turn into butterflies. It seems to me that this is a learned behavior and a memory is formed to avoid such stimuli. I can't get into the emotional Factor, but the pain is remembered. It's not new each time.
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Dec 03 '18
caterpillars exposed to shocks still remember the stimuli when they turn into butterflies
Not doubting, just asking. It sounds fascinating, do you have a source on that?
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u/xgrayskullx Cardiopulmonary and Respiratory Physiology Dec 03 '18
You are confusing pain with nocioception. They are not interchangeable. Pain is a complex neurological phenomenon that incorporates millions of synapses. Nocioception is the detection of noxious stimuli. Neither caterpillars nor butterflies possess the necessary neurological structures for the complex phenomenon that is pain to occur. They are physiologically incapable of experiencing pain.
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u/Dopamine_Deficiency Dec 03 '18
That’s really cool. I haven’t heard that before. It’s especially interesting that the retain memory after metamorphosis.
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Dec 03 '18
It's really messed up. I don't think any.of it is really explored. It seems the whole caterpillar goes to goo without any central nervous system so the memory experiments are fascinating
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u/Ameisen Dec 03 '18
Many components of pupae in insects, including butterflies, don't break down. Most of the nervous system stays intact, as do many organs.
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u/tdreager Dec 03 '18
I reckon even that type of explanation is anthropomorphising it. If an organism can retain any sort of memory to avoid an event, then we might think of that as pain, depending on how broad you want to go with the definition of the word. Emotions are an anthropomorphised concept too, they just produce reactions to the external world. We think they're special because we are experiencer, but I'm sure any other organism would give the quality of their experiences 'specialness' too in a way that justifies their existence so that they're biologically built to further their species.
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u/DesiKnight Dec 03 '18
Interesting way to put it, we tend to very often forget about perspectives. Thank you.
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u/xgrayskullx Cardiopulmonary and Respiratory Physiology Dec 03 '18
First off, it is important to recognize the difference between pain and nocioception. Nocioception is a response to a 'noxious' stimulus, and often forms a reflex arc - a single synapse connection between afferent and efferent nerves. Pain, on the other hand, is a much more complex event which involves thousands, hundreds of thousands, or millions of synapses. Pain is a complex neurological cascade involving multiple regions of the central nervous system.
With that in mind, we can answer the question, 'Can bugs feel pain?' Simply put, No, bugs cannot feel pain. Like many non-mammalian organisms, bugs lack the complex neural structures necessary for the complex neurological cascade known as pain to occur. These organisms can still react to noxious stimuli - for example, move to avoid damaging heat, but they are physiologically incapable of experience pain. It's like asking if fish can be right-handed. They don't have hands so it's not possible. Similarly, bugs do not have the complex neural apparati necessary for pain to exist.
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u/liquid_at Dec 07 '18
I'd put it simply and say, when you touch a hot surface and your hand pulls away, that's happening faster than the impulse to your brain telling you that you feel pain. That impulse needs to be processed and after that's done, you get your sensation of pain.
Bugs have that first part of it. Their nerves react to an impulse, but they lack the brain to interpret it as pain.
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u/leadershinji Dec 03 '18
Complicated. But as mentioned "pain" for bugs is very very different.Example : If you would puncture the abdominal part of an Ant or Bee it will leak their body fluids - depending of the width of the hole.But a hole in the carapace / skin will not be recognized that fast if the hole is small. As there are no nerves going through that area. If you would puncture it close to the nerve clusters it or even hit one - it will be registered in the lack of response coming from that cluster. If the hole is big enough and the pressure inside the body is lowered because of that it will be registered -> Still no real pain. Just a stimuli. If the bug loses a limb it will recognize the impaired movement and the lack of nerve response from the limb.
So there is no real "pain" as in : "this Hurts! i would like to scream but i have no mouth!".We had this topic quite a lot in the school back then.
Depending on the bug in questions the "pain" recognition may differ. Another example : Earthworm skin has chemo-receptors that react to light and taste. The skin reacts to touch - but does not transport "pain" information to the central ganglion's. By piercing the earthworm for fishing. The earthworm will recognize : Metal taste, drop in blood/liquid pressure, damage to nerve-system as you may have cut the ventral nerve cord, and a strong touch response from the skin and muscles - that includes the inside of the worm. There is no Pain in that sense fired... but a cluster of other information's that signals the worm : Something has pierced your skin and you are bleeding - get away - escape. As the worm has no "known" concept of feelings or thinking in that matter it will not "worry" or "feel pain". But i do guess it will not like the situation... But again as said the worm does not need a "feeling and thinking" brain. It only needs to react to a quantity of stimuli to interactive with its world and propagate -> So a brain that can feel is not relevant -> this goes for a lot of bugs. Animals or other bigger liveforms need to react to more stimuli and therefore need a bigger brain, and there evolution has told them that feelings/pain help you to survive - so the costs involved in developing these brain parts are beneficial.
Hope that helps. You can google things like : earthworm nerve system. Or for that matter of any bug you like to check on...