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It is currently common for people to feel little or no duty of care towards insects.  In this post, I make a case for why I think expanding our circle of compassion to insects is both rational, and important. 

*I think the arguments also apply to other invertebrates such as shrimp and gastropods (slugs and snails) but for simplicity, I’ve kept this post focused on insects.

Why is this important?

The sheer number of insects whose lives humans have the power to affect is huge. A few bits of relevant info to demonstrate the scale:

  • Around 1 trillion insects are raised and slaughtered on farms annually for food and animal feed. A single farm could have 29 billion insects alive at any one time. And the insect farming industry is looking to expand rapidly in coming years, despite concerns about welfare.
  • In the wild there are an estimated 10 quintillion (10 with 18 zeros!) insects alive at any given time. Many of these are harmed by pesticides and other human activities.
  • Across the world, it is generally legally and even socially acceptable to harm insects. For instance, the boiling of silkworms alive is part of the process for making most silk. As a kid, I owned a children’s ‘fly-splatter’ gun which was sold as a fun toy.

Despite the huge numbers of insects who are farmed and harmed by humans each year, the topic of insect welfare is currently highly neglected. There are very few organisations working on the issue (although shoutout to Rethink Priorities, who have produced some great research) and I'd be surprised if even 0.01% of the animal advocacy movement's resources are currently going into insect welfare work.

So, to summarise: the scale is huge, the welfare issues often serious, and the situation completely neglected.

A selection of arguments

The aim of this post is not to go deep into the science or philosophy of insect sentience. Rather, it is to offer a brief selection of arguments in favour of caring about insects. 

You may not agree with every single argument in this post. But my hope is that, as a whole, they make a case for each of us to feel a deeper sense of moral concern for insects.

1. The science: behaviour

The scientific literature on the behaviour of insects (a hugely diverse class of animals) is generally under-explored.

A great in-depth review of what we know about invertebrate behaviours, including insects, can be found here. I think the key takeaway is that invertebrates are capable of some quite surprising and complex behaviours, which suggests they are conscious of the world. 

Just a tiny selection of studies demonstrating these behaviours in insects:

  • Honeybees have displayed pessimistic cognitive biases after being exposed to a threat, as well as positive emotion-like states following exposure to unexpected rewards.
  • Funnel ants were able to use absorbent objects to transport sugar water back to their nest, quickly learning that sponges were the most absorbent material and using them preferentially.
  • Fruit flies are likely affected by painkillers in a similar manner to humans and are willing to endure a cost (e.g. an electric shock) in order to receive a reward.

Of course, none of these studies prove that insects are conscious. But, the existence of such complex, flexible and emotion-like behaviours suggests that they are not simply carrying out an unconscious pre-programmed set of behaviours.

2. The science: nervous systems

Again, the current science on this is pretty spotty. However, Rethink Priorities have done some excellent work collecting the evidence on this. I've also written on it, but Rethink's stuff is way more comprehensive!

I think there are two key takeaways from what we know: 

  1. It's not clear that a 'large' brain is required to support sentience.
  2. Insects have brains which plausibly could support consciousness.

On point 1, it's easy to get bogged down in philosophy. So I'll simply note that it's likely that the structure of a brain is just as important (up to a point) as its size (in number of neurons). For example, it appears that the tiny brain of a honeybee is capable of supporting a greater number of distinct behaviours than the (obviously) much larger brain of a moose.

Credit: Animal Ethics

On point 2, insects have been found to have brains that contain structures similar to the mammalian mid-brain. These structures are thought to be important for consciousness in mammals. There is also a reasonable degree of centralisation in the insect nervous system, which is thought to be an important requisite for consciousness.

In summary, the literature suggests that having a big brain isn't essential for consciousness, and that insects have brains which have features considered very important for consciousness.

3. Outwards and outwards...

Throughout recent human history, our moral circle has gradually expanded outwards. Our ancestors often kept groups including slaves, other races, and disabled people firmly outside of their moral circles. Thankfully, the complete exclusion of these groups from moral consideration is far less common in the modern world.

The expansion of humanity's moral circle has also brought some animals into the fold. We now look back with disbelief at the renowned philosopher Descartes' assertion in the 1600s that all animals were 'automata' unable to think or feel. 

150 years ago, it was legal in the UK to dissect a living dog without anaesthetic. 

It was only this year that the UK government recognised the sentience of decapod crustaceans (crabs, lobsters, etc.) in law for the first time.

So, we have gotten it wrong on animals many times before. At every other moment in human history our moral circle has excluded animals which, in hindsight, should have been included. As science begins to reveal more about the complexities and capabilities of insects, what are the chances we’ve gotten it wrong again?

4. Our brains don't make caring easy

Anyone interested in EA knows that moral psychology is an odd thing. You might believe that every human life has equal worth - and try to live your life by that - but you probably don't always feel that way emotionally (which is fine, it's important to feel a stronger bond with your family and friends than with a stranger).

Unfortunately, insects get a pretty rough deal when it comes to human psychology. Evolutionarily, an insect such as an ant is just much further away from us than a cute fluffy hamster is.

Research shows that humans have less empathy for species that are more distantly related to us evolutionarily. We are evolutionarily primed to care for other humans. So it makes sense that we would feel more empathy for animals with more human-like features. As a result, we are instinctively wired to adopt a less compassionate attitude towards insects than our fellow mammals.

Chart showing how empathy and compassion decrease with increased evolutionary distance from humans (insects are roughly on a par with plants)

Insects are also, well... pretty small. That means that we're less likely to see their world and empathise with their suffering. If your cat catches a rabbit, you see how it suffers. If you accidentally step on an ant, you don't even notice. 

We should acknowledge that we are naturally set up to be pretty rubbish at feeling empathy for insects. But - crucially - looking weird, scary, or just being hard to see doesn't affect whether they can feel pain. So our instincts about insects are likely to be wrong, and we should try to adjust accordingly.

5. Where's my warm fuzzy feeling?

The arguments I've briefly presented above (I hope) make some sense. But the reality is that we're not super-rational philosophy machines, so even if you think my arguments are persuasive, you might not really be feeling much different about insects.

Sadly, we don't have/make many opportunities in life to really connect with the lives of the insects (and other small animals) around us. So as a final argument, I present to you an incredibly wholesome video of a bee and the woman who cared for her.

It's not scientific, but perhaps it might give an emotional kick to something that you sympathise with on a rational level (or maybe not, you might totally disagree with everything above!).

I'd love to hear your thoughts!

Thank you for reading. If you have any thoughts, questions, or challenges, I'd love to discuss them in the comments section with you!

Thank you to Ellie Crane for her contribution and edits to this post.

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As someone who has been concerned about insects as an area for years, I think the aspect that stops animal-focused people I speak to from engaging with insects as a cause area is not really to do with scale or neglectedness. Many vegans do not eat honey; suggesting a concern for the bees creating it, and SWP (https://www.shrimpwelfareproject.org/) has gotten quite a lot of support from the animal movement. The issue is pretty directly tied to tractability and concrete actions that can be taken. If the current inventions focused on insects are research-orientated with unclear pathways for how insects do in fact get helped, that will be a blocking factor for many EA animal advocates. I think in many cases right now, people see insect welfare much like wild animal suffering; as an interesting, high scale area with no clear significant actions that can be taken.

In expanding what  Joey said, I think another aspect of why insect work may be a bit less tractable is to do with optics. I think in the broader public sphere, insect farming has been seen as a potential solution to food insecurity and a sustainable agricultural solution requiring less land and water etc. This may make it somewhat harder to gain significant traction in the space. 

That being said, I think one particularly large area where work might be interesting in working on is slowing down insect farming for animal feed, which I imagine would cause less public disagreement than slowing down insect farming for human consumption purposes. 

Another introductory post about why one may want to care about insect welfare: Does Insect Suffering Bug You? - Faunalytics (Jesse Gildesgame, 2016).

Recently, activists have started campaigning against silk because they believe the production process is cruel to silkworms. Many people respond to these campaigns with skepticism: who cares about silkworms? It’s easy to feel for the chinchillas, foxes, and other furry mammals used in fur clothing. But insects like silkworms are a harder sell. It seems crazy to grant moral consideration to a bug.

Nonetheless, the idea that we should care about insect welfare has been gaining credibility among activists, scientists, and philosophers in recent years.

[…]

The question of whether insects can feel pain or have other negative subjective experiences is hotly contested among scientists.12 Amid the uncertainty and debate, one thing is clear: at least for now, we can’t be sure. Whether or not insects have the capacity to suffer is still very much an open question.

If insects can suffer, they probably suffer a lot. Starvation, desiccation, injury, internal organ failure, predation, infection, chemical imbalances, and other stressors are common features in a bug’s life.13 It’s possible that insect lives are full of suffering.

Should we be worried?

Since the science isn’t clear, we should assign a nontrivial likelihood to the hypothesis that insects suffer. However, even if you think the likelihood that insects suffer is extremely low, it’s worth keeping in mind just how many insects there are. Their sheer numbers suggest that if they do suffer, the scale of the issue would be enormous. […]

What should be done, if anything?

[…]

Even if we should prioritize vertebrate welfare, there are things we can do to mitigate the risk of insect suffering that don’t impede efforts to promote vertebrate welfare.19 We can replace silk with polyester or rayon. We can develop and improve standards for the humane use of insects in research. We can help farmers choose pesticides that limit possible insect suffering. We can also take care to avoid hurting insects in our daily lives in a number of ways.

It might turn out that insects don’t suffer, but until we know, it’s a risk worth taking seriously.

A suggested explanation for our indifference

During a  cursory reflection on my own perspective of insects after reading this, it occurred to me that maybe interpretable behavior and reactions are what reaches out to our minds and causes emotions.

 Animals like cats, dogs, and hamsters experience the environment like we do. Similar things are perceived as threats, resources, etc. So while they do not talk to us, their actions and reactions are easy to empathize with. Their actions and reactions can speak to us in a way, telling us that they are confused, scared, curious, etc. Also, their actions can serve as a kind of common language between us, such as a dog barking telling us there may be a threat, or a herd of mammals running from a certain direction telling us there is probably a threat coming from that direction. 

Insects, on the other hand, experience the environment in profoundly different ways. To experience what they experience would be akin to being shrunk to the size of a marble and seeing refrigerators as giant statues and slight breezes as dangerous winds. 

So, without a shared experience of the environment, their actions and reactions don't speak to us, nor do they have any semblance of a common language, and so they don't reach out to our minds and cause us to feel emotions.

Given this explanation is true, my response

Obviously, we have evolved without an experience of the environment that is common to insects. Therefore, it is in our nature to be indifferent to insects.

However, that is not a justifiable excuse to be indifferent to them. A legacy of not having a common grounds with them is not a reason to continue ignoring and being indifferent to them.

Thank you for your post. You present a well-reasoned and fascinating case for extending our moral circle to include insects. 

I am an enormous insect lover and I have become hugely preoccupied with learning more about their subjective experiences and to what degree insects experience suffering. A couple of years ago I researched how the human consumption of insects–entomophagy, could support resilient diets. Initially, I was so enamored by the favorable land/water use of insect farming that I could largely overlook the ethical concerns behind entomophagy, but I have updated since then and grown increasingly more concerned about the ethics. 

Here is an article I published about entomophagy largely extolling the environmental and nutritional upsides of insect consumption. 

Here is a section on ethics that didn't make it into this version of the rticle, but that I am looking to expand and revisit:

Ethics of Entomophagy 

The ethics of eating animals is a question that provokes perennial philosophical interest. The eating of insects should be met with as much moral and ethical discussion as would surround the eating of any other living creature. According to Rozin & Ruby (2019), “the general lack of moral objection to raising insects for food is predicated on the belief that they do not suffer in the process; if this is untrue, then raising insects for food rather than larger invertebrates may actually increase overall suffering, given the much larger number of insects required to make one kilogram of food” (p. 161). Given the enormous quantity of insects that widespread entomophagy would require, it seems necessary to investigate further into insect suffering. 

In 2005, Author David Foster Wallace wrote an article on the eating of lobsters that continues to perturb and inspire ethicists and laypeople today. Beginning as a review of the Main Lobster Festival, the article quickly evolves into a provocative philosophical analysis of the ethics of eating lobsters and how human beings consider, or more often don’t bother to consider, animals’ pain when it’s up against gustatory pleasure. Foster Wallace posits that when considering animal pain “...everything gets progressively more abstract and convolved as we move farther and farther out from the higher-type mammals into cattle and swine and dogs and cats and rodents, and then birds and fish, and finally invertebrates...” (p. 62). An investigation into the ethics of eating invertebrates such as insects will be difficult, but how insects are raised, harvested, and ultimately consumed is inextricably linked to how sustainable and moral the practice of entomophagy can be.

Final thoughts:

I would absolutely love to talk about this further. I think that insect farming will proliferate in the next few years and that there may be significant environmental benefits to this. However, I fear that the downsides will far outstrip the positives, especially if the following are true. 

  1. If insect-derived animal feed replaces/supplements soy-based feed and cheapens or enables the expansion of factory farming.
  2. If insects suffer tremendously or if the cumulative suffering is staggeringly high. 

    Please reach out to me to talk more about this. I would also be extremely curious to get involved with research about this or other projects involving insect suffering/humane insect farming/entomophagy.

I think a lot of this makes sense for the general public, but I agree with other commenters that a lot of vegans do think insects are worthy of care or at least use the precautionary principle to avoid honey and silk. 

I'm one of those people and I do think insects suffer but I still have less interest in putting a lot of resources in this direction. My perception of lower tractability is part of it, but it's also that even for those who do think they suffer, we are just barely sure of that. I would guess that the experience/scope of suffering for such a simple organism is qualitatively different from vertebrates, so the scale arguments don't hold as much weight to me. 

To take one aspect of suffering, there's a qualitative difference between suffering in the moment and having any concept of the fact that you have been suffering for however long, and another layer of qualitative difference between that and realizing you're likely to continue suffering in the future. Most adult humans can do both, and I would guess that insects can do neither, while other vertebrates fall somewhere in between. Add to that all the other dimensions on which suffering likely differs and to me it becomes almost meaningless to compare the scale. As an analogy to qualitatively different types of human suffering, I don't have the slightest idea how one would weight quadrillions of bullying experiences against millions of murders. 

I'm hardly an expert, but that's my sticking point.

TL;DR - Thanks for an interesting and accessible post! With the caveat that I've done no research and have only anecdotes to back this up, I wonder if you may underestimate people's intuitive ability to feel empathy for insects. Perhaps the more daunting obstacle to social concern for insect welfare overlaps with our indifference toward wild animal welfare in general?

***

When I was about 7, one of my young neighbors used to pin large mosquitoes against his playset slide and slowly tear off one limb at a time.* My siblings, parents, and I universally found this repulsive, long before we knew anything about EA. As Brian Tomasik documents in some of his videos, many insects writhe as they die in ways that humans typically associate with pain.

They also attempt to escape death in ways we understand as fear. I used to live in a place with lots of American cockroaches, which are large enough to be gross and startling. I probably squashed 50 - 100 of them over the years. Each time, I couldn't help but feel conflicted chasing them, then applying enough force to feel them burst under a wadded paper towel as they frantically scurried to escape. "If the Jains are right," I joked to a friend, "I'm going to hell."

My reflection from these biased and highly unscientific anecdotes is that even if we do not intuitively feel a moral obligation to protect or care for insects, ensure they live flourishing lives, or even refrain from killing them when they annoy us (or legitimately threaten our health/hygiene), we do at least dimly suspect they are capable of pain and negative emotions and feel an obligation not to gratuitously intensify that suffering. We kill bugs, but we prefer to give them a quick death. That's arguably similar to our moral intuitions for other animals. Most people object to dogfighting much more than they object to putting down unwanted strays in a shelter, for example.

For this reason, I do think "don't boil silkworms alive" could eventually catch on as a mainstream cause. So could "don't farm insects in stressful conditions" and "ensure pesticides kill only the desired insects, as quickly as possible." We can be convinced to mitigate whatever unnecessary suffering we are directly responsible for, especially when the required sacrifices are minor. I'd be glad to see EA get involved in this work.

On the other hand, these intuitions will not reach the overwhelming majority of those 10 quintillion insects, and I suspect you'll struggle to convince most people to go further than that. My hunch is that this is for the same reason people are skeptical of wild animal welfare in general. Most people's moral intuitions have at least some deontological streak, so they feel much more responsible for animals that suffer at human hands than they do for those that suffer from natural predation, starvation, infection, etc. When we watch one animal eat another in a nature documentary, we may feel some compassion (admittedly proportional to how cute the eaten animal was). But we do not feel guilt or responsibility to change our own behavior in the same way we might if we were to have personally hunted or eaten the animal.

So my theory is that even though insects are uniquely small, weird, or scary, we can empathize with them in similar circumstances to our empathy for other animals. Nonetheless, this empathy isn't enough to reach most suffering insects. 

If this theory is true, it has implications for what strategies are likeliest to succeed in improving insect welfare, as well as how we should categorize insect welfare among other EA causes. Whereas factory-farmed chickens represent the overwhelming majority of overall chickens on Earth, farmed insects are a tiny minority of overall insects, and seem likely to remain so. In this way, insect welfare could be seen as a speculative but high-stakes subset of wild animal welfare, the tractability of which may depend on similar advocacy approaches.

Thanks for a really interesting comment Andrew! I think you're definitely correct that we shouldn't underestimate people's moral concern for insects. I recently saw this poll by Rethink Priorities which shows that around half to two thirds of Americans believe that insects can feel pain, which isn't too far off the kind of responses you get when you ask about fish.

I think ultimately insect welfare is currently so overlooked for a mixture of reasons, not just the lack of empathy that I address in my post. And I think you're spot on in identifying that the wild/farmed distinction is probably a key part of this.

*(Note: This neighbor threatened me with a kitchen knife when we were both eight years old, and seemed generally prone to violence and antisocial behavior. So I don't think his apparent indifference to mosquito suffering should be taken as a counter-example suggesting that most people are also indifferent.)

Thank you for a well written post. The fact that there are 10 quintillion insects makes it hard to care about insect welfare. At some point, when deciding whether it is effective to improve insect welfare, we have to compare to the effectiveness of other interventions, like improving human welfare. How many insect lives are worth one human life?

This is just estimating, but if the answer is one billion or less, then I should care more about insect life than human life, which doesn’t seem right. If the answer is a quadrillion or more, it seems like any intervention will not have sufficient impact. Therefore this only makes sense with an ethical theory that places one human life between a billion and a quadrillion insects.

I’m not sure what the right answer here is but it seems like something that needs a good answer in order to claim effectiveness.

This doesn’t seem like the ideal reasoning I would use.

On one hand, the fact that animal life is worth a lot (ratio is “one human life is worth less than a billion”) can’t be a reason to be skeptical by itself—you either determine this is true or it isn’t (which can be very hard admittedly).

If animal life’s “tradeoff ratio” to other life is too small, it is entirely possible it is too small to be an effective intervention. But it’s not based on feelings or a numerical cutoff but instead many factors of impact and effectiveness.

This post is well-intentioned and the bee story is sweet but beyond avoiding pulling wings off flies I don't see what more we can do.

Assigning anything above the tiniest value to the welfare of insects leads to absurd conclusions because of their sheer number .eg.:

  • Should we stop using pesticides and increase food prices/slow development because of insect welfare?

  • Should we start killing whales, birds, fish because the number of krill/insects they eat?

  • Do we need more rather than fewer locust plagues?

  • Should I let termites eat my house actually?

Widening our moral circle out this far is impractical.

There are a number of thing we can do:

  1. We can get a sense of the suffering of individual insects
  2. We can stop or slow down the human factory farming of insects, which would affect a lot more organisms than any farming so far.
  3. We can stop reexamine using certain kinds of insect control, such as insecticides that might a lot of suffering (although insecticides may be important for their value in constant suppression to prevent large unnatural populations). EDIT:  added more detail to use of insecticides. 
  4. Below is a map of the USA showing the land dedicated to agriculture. It seems like many insect populations exist directly from agriculture land or otherwise are influenced by decisions on agricultural land (locusts). It is possible that innovations or changes in ag policy can affect insect populations that comes from crop land.
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