Thoughts on the welfare of farmed insects

byMaxCarpendale12d8th May 20199 comments


This post is quite preliminary and abstract. I have not looked deep enough into the relevant literature on how insects are currently farmed to recommend concrete and specific proposals, only general considerations based on theory.

This article is principally about factory farming insects for the purpose of eating them. Some of it may also be applicable to humans raising insects in other conditions, such as for shellac, honey, and silk. The idea of farming insects for human consumption has become quite a prominent discussion topic, and many insect farming for human consumption operations have been appearing. I think it’s important to prevent this spread, or at the very least push it in a more positive direction. I’ve been focusing on invertebrate consciousness and suffering research over the last year, so this seemed like a natural extension of my focus.

This post is about how we might be able to improve the welfare of farmed insects through welfare measures. As with other posts focusing on welfare, there is some risk that this post could be seen as supporting or endorsing the practice of eating insects, as long as some minor welfare adjustments are adapted. In fact, I’m sceptical that even in an ideal insect farming operation adequate welfare measures could be adopted to give the insects lives worth living, and as the factory farming of other animals has shown us, these operations tend to use far from ideal welfare measures.

Though it is not clear if insects are phenomenally conscious (and so if they can suffer), I think that we should take precautionary measures now to avoid moral catastrophe. Expert seem to be divided on the question of insect consciousness. Because insects are so much smaller than animals that we currently factory farm, vastly more individual animals would have to be raised in horrible conditions to produce the same amount of meat. This would potentially raise the expected amount of suffering by many orders of magnitude.[i]

At least in Western countries, eating insects is currently seen as disgusting. I would expect there to be fewer hurdles associated with getting clean meat adopted by Western consumers than insect meat. Insect meat is also at least currently typically very expensive. This calls into question what if any benefits anyone is supposed to be getting from pushing for the adoption of insect meat when we have plant-based alternatives.[ii]

Some reasons why it may be hard to raise farmed insects to live good lives

Factory farming practices tend to foster a ‘race to the bottom’ environment in terms of welfare standards, causing tremendous suffering to the animals involved. Modern advocates of insect farming have allowed themselves to imagine idealized farming techniques that might be used, rather than the methods that seem most likely. This is hugely problematic for the potential insects involved. People seem to have a much easier time caring about the much larger and more charismatic animals that we currently factory farm, and yet there still hasn’t been enough pressure to reduce the suffering of factory farmed animals. We should therefore expect insect farming to be even worse, not better.

Even if we could give them lives worth living, there are real questions about if a society that still ate animals (such as insects) could bring itself to care about their well-being to the extent that they should. For these reasons, the abolition of animal farming should be the ultimate goal, though improving welfare measures could be a useful proximate goal.

There are a couple of factors that make raising insects in a humane way difficult. The first is that insects usually invest very little in each offspring, which tends to mean that they are prone to early deaths. This may mean that it is hard to raise them without frequent deaths. One study found that 99% of crickets fed on relatively unprocessed food waste or straw died within three months.[iii] Probably to avoid this high mortality rate and improve growth rates, most insect farming operations feed crops to insects.

Keep in mind that this removes the main argument used for insect farming, which is that it could be more environmentally friendly because they could be fed food scraps that might otherwise go to waste. It also removes the argument that raising insects for human consumption could be better than eating plants because crop cultivation involves using insecticides that kill insects and so, they argue, more insects would be killed this way. If crops have to be fed to insects for them to grow, this means that at least as many additional insects will have to be killed by insecticides (in addition to the suffering of the insects being raised for food). The conversion ratio of crop to insect meat is much better than it is for either types of meat, but still is not as efficient humans eating the crops directly.[iv]

It may be that many species of insects are just not built to have high survival rates, even if they were raised in good environments. Arguing that farmed insects could have higher welfare than wild insects is not sufficient to establish that insect farming is not harmful or is beneficial to the insects involved because it is very questionable whether wild insects live lives worth living.

Another general problem is that insects are very small and numerous so any kind of individualized treatment for specific injuries or diseases would be prohibitively expensive. For example, if a farmed cricket caught a disease or was injured, no one would help it and it would be left to suffer and potentially die. The nearest solution that might be adopted for this is antibiotics or pain relieving drugs in the insects regular feed, but there are likely other problems associated with these.

We also understand much less about how insects feel pain and what stimuli cause them the most pain, so it’s hard to be as sure that a method is relatively humane. Relatedly, insects are harder to fully kill or render unconscious in a conclusive way. This probably makes it more difficult to find a more humane way of killing insects. This is because insects have a less centralized nervous system (think of the fact that cockroaches may survive for a while without their heads). This may mean that isolated parts of their nervous system might still continue to function and potentially register pain even after massive bodily damage. This is a very concerning possibility, since it would greatly multiply the amount of time that insects spend suffering from the most painful injuries.

I’ve heard it argued that insects might leave better lives than other livestock because they have less need for an enriched environment and it is easier to provide them with an environment that they would enjoy. This is some plausibility to it, but I think we don’t know enough about what insects find rewarding to prove this. Insects also have evolutionary incentives to engage in many different kinds of behaviour. The way that evolution gets humans to engage in evolutionary productive behaviour is to make us enjoy those activities and we have some reason to think that it would be the same for other animals including insects.

To take the example of crickets, it seems to be important that crickets mate, sleep, eat nutritious foods, hide, avoid stimuli associated with predators, avoid poisons, avoid diseases, avoid overcrowding, maintain dominance, maintain healthy temperature, engage in flying, engage in digging, explore their environment, maintain optimal light exposure, and make noises to attract mates if they are male. Crickets are one of the main types of insects raised for consumption. This list may be a little bit shorter than it would be for larger animals (for example there is no strong evidence of play behaviour in insects), but it is still a considerable list of requirements, and I’m sceptical that modern insect farming operations meet these criteria.

In general there are more ways for the life of an animal to go wrong then there are the life of that animal to go right, and this is a big problem when raising these animals when research is lacking.[v] It is true that it is somewhat important for people who farm insects to keep them alive and healthy to maximize the amount of good meat that they produce, but this is also true in traditional factory farming situations and it has definitely not ensured that those animals live good lives. Factory farming has been the recipe for the perfect misery of those animals.

Methods of killing insects:

One common method of killing insects seems to be freezing them. As far as I know there is no good evidence that this should be a less painful way of killing these animals. There is some evidence that crayfish may not feel pain in response to cold temperatures, but these are marine organisms and so they are at less risk of temperature extremes than other animals. Even C elegans, the nematode worm with ~300 neurons, avoids extremes of heat and cold.

Some have justified this as a way of killing species of insect that undergo torpor (a state of reduced activity) in response to cold. The idea is that the cold would put them into a state of unconscious torpor before finally killing them. While it is plausible that these species might experience less pain from this than other species, I haven’t seen this properly justified as a less painful way of killing these animals.

Since insects in general are poikilothermic, they can survive at a wider range of body temperatures than birds or mammals can. Though they operate less well when cold and so still have an evolutionary incentive to avoid cold temperatures. One guide to collecting and killing insects to take as specimens notes that it may take more than a day to kill insects by putting them in a freezer. This sounds like a ghastly way to die, assuming they are conscious for any significant portion of that period.

Other sources blend them alive into a powder if this could be done very quickly and reliably it would have the advantage of decisively killing the animals. This would have my bet as the least painful method of killing of the options considered in this article. Some farms claim that they can kill within one second. My own intuition is that even if it was a very painful second, it would still be much preferable to any protracted form of killing. But opinions differ on this point and relevant research is lacking.

Many farmed insects are also raised for live consumption which means they will not be killed at all humanely. Also, we are unlikely to enforce any welfare standards on backyard insect farming operations for personal consumption. Despite this, sources such as the FAO still recommend promoting backyard insect farming operations.[vi]


My general position is that I expect insect farming to be even worse ethically than the factory farming of larger animals. It is good that advocates of insect farming for human consumption feel the need to address the topic of welfare, but I find their arguments on the subject weak and wishful. This article is an attempt to balance out that discussion. This is a subject that we need to be especially rigourous about.


Many thanks to an anonymous donor for suggesting the subject and funding me to write the post. This post is quite heavily based on the work of Brian Tomasik.

[i] Even if you think that insects might suffer less than larger animals, I don't think it's likely that they suffer vastly less to make up for the many additional insects that would have to be raised. I think there are a lot more reasons to think that insects are conscious that you might naïvely expect given their size, and their brains are larger and more efficient than you might expect. There are also some reasons to think that insects have faster subjective experience clock speed, which is a factor suggesting they have greater capacity for suffering and happiness than larger animals.

[ii] See Nicole Rawling’s presentation in this video or the transcript to see these arguments in more depth. h's ttps://

[iii] See also "Insects intended for human consumption need to be fed feed grade or even food grade food if the insects are not to be degutted." Van Huis, A., Van Itterbeeck, J., Klunder, H., Mertens, E., Halloran, A., Muir, G., & Vantomme, P. (2013). Edible insects: future prospects for food and feed security (No. 171). Food and Agriculture Organization of the United Nations.

[iv] " Typically, 1 kg of live animal weight in a typical United States production system requires the following amount of feed: 2.5 kg for chicken, 5 kg for pork and 10 kg for beef (Smil, 2002). Insects require far less feed. For example, the production of 1 kg of live animal weight of crickets requires as little as 1.7 kg of feed (Collavo et al., 2005). When these figures are adjusted for edible weight (usually the entire animal cannot be eaten), the advantage of eating insects becomes even greater (van Huis, 2013). Nakagaki and DeFoliart (1991) estimated that up to 80 percent of a cricket is edible and digestible compared with 55 percent for chicken and pigs and 40 percent for cattle." Ibid.

[v] This is an extension of the Anna Karenina principle that Magnus Vinding mentioned in conversation.

[vi] "Procedures for small-scale farming should be developed – such as kits for home-use – so that people can easily start small-scale rearing facilities" Van Huis, A., Van Itterbeeck, J., Klunder, H., Mertens, E., Halloran, A., Muir, G., & Vantomme, P. (2013). Edible insects: future prospects for food and feed security (No. 171). Food and Agriculture Organization of the United Nations. The