Why eating insects may be the most ethical option. An argument by u/Shark2H20:

Like with bivalves, if we’re unsure that insects are sentient, treading carefully and not killing them for food seems to be the right thing to do, since acting cautiously seems morally better than acting recklessly. But things get a little complicated, as I’ll explain below. One version of a risk-averse precautionary principle goes like this:

“If You Don’t Know, Don’t Kill”

”If someone knows that they don’t know whether a living organism has significant moral status or not, it is morally blameworthy for them to kill that organism or to have it killed, unless they believe that there is something of substantial moral significance compelling them to do so.” Source

Seen in this light, entomophagy — the practice of eating insects for food — appears ethically hazardous, since it potentially involves exploiting a huge number of morally relevant beings. Entomophagy could also seem risky because it potentially involves killing a huge number of morally relevant beings in inhumane ways, as entomophagy can include boiling, frying, steaming, roasting or eating insects alive. https://reducing-suffering.org/why-i-dont-support…/…

Like the ethical invertebratarian, however, morally sensitive bug eaters — call them ethical insectivores — may point to the last part of the principle I quoted:

“unless they believe that there is something of substantial moral significance compelling them to do so.”

Assuming that killing’s harmful, the ethical insectivore can point out that all large-scale food producing systems fail to be harm-free: raising crops generally involves killing a non-trivial amount of mammals, birds, reptiles, amphibians and, yes, lots of insects too. So, especially if insects on insect farms are fed food waste, then insect farming may actually cause fewer deaths than plant agriculture, given a number of assumptions (see below). The ethical insectivore could argue that we have reasons of “substantial moral significance” compelling us to eat insects, appealing to a “least harm” principle that advises us to act in a way that causes the least harm. (Making a comparative case like this in terms of harm, though, may be difficult — if not impossible — since empirical studies about how many wild animal deaths occur during crop production are seriously flawed.)

The ethical insectivore could also object to the moral precautionary principle I described because this principle fails to recommend how we should act in cases where avoiding one moral risk involves taking on another. That is, if the choice is between the moral risk of entomophagy — which involves killing a vast number of beings whose moral status we are unsure about — and raising crops — which includes killing a non-trivial but unknowable amount of beings whose moral status we are more sure of — then it’s unclear what we should do. (Imagine a trolley problem situation where we have millions of insects on one track and a non-trivial but unknown number of mammals and birds on the other.) To solve this dilemma, the ethical insectivore can suggest we follow another, more detailed, and possibly more helpful moral precautionary principle, like this one:

The Rough Estimates Precautionary Principle

(1) In cases where a particular individual is probably conscious, and treating that individual as conscious wouldn’t prevent us from fulfilling our obligations to any being that is definitely conscious, we ought to treat that individual as though it’s definitely conscious; (2) in cases where a particular individual is perhaps conscious, and treating that individual as conscious wouldn’t prevent us from fulfilling our obligations to any being that is definitely or probably conscious, we ought to treat it as definitely conscious. https://link.springer.com/article/10.1007/s10806-015-9599-y

A moral principle like this, if true, would appear to imply entomophagy (or at least a cleaned-up version of it where the insects are killed painlessly), since our moral obligations to those creatures killed during crop production who are definitely or probably conscious (mammals, birds, reptiles amphibians) are stronger than our moral obligations to creatures who are merely perhaps conscious, like insects. If eating insects cuts down on eating crops — which would be a way of favoring our duties to the “probably conscious” over our duties to “perhaps” conscious — then maybe ethical insectivores are onto something.

Personally, I’m not sure how I feel about these arguments. I will say right away that if the main moral problem with animal agriculture is the use or exploitation of animals, and if we believe insects have moral status, then insect farming can be rejected immediately, as it would add enormously to the total amount of used or exploited morally relevant beings in the world. The cultural embrace of yet another practice that involves animal exploitation would be quite clearly a move in the wrong direction, as far as many vegans are concerned. If insect farming has the effect of more deeply entrenching a norm of animal exploitation, so much the worse for insect farming in terms of harmful consequences.

But if we are more concerned with reducing harm (and we are unconcerned about the possible harmful side-effects of insect farming) then, again, things may favor insect farming over plant production. Part of the issue probably depends on the question of what these insects are fed before they are eaten by us. If insects on insect farms are fed crops grown especially for them — if they are not fed “food waste”, then eating a plant based diet may have a smaller overall harm foot print than entomophagy. But if the insects are fed food waste, the opposite may be true.

However these estimates involve a lot of assumptions, including a calculation of expected utility. I’ll quote the relevant section of the paper I’m working from in full:

expected utility—a kind of cost/benefit analysis where all costs and benefits are expressed in a common currency. That currency is utility, a unit of well-being, which can be either positive or negative. As you might imagine, there are enormously complex philosophical questions that come up when we try to specify what a unit of well-being represents, and even more difficult questions when we try to compare units of well-being across species. (For discussion, see Alexandrova (2015) and Rice (2016).) However, this is not the place to delve into these difficulties, so we will simplify things by focusing on the expected number of deaths. (Granted, an expected death estimate is unlikely to be a perfect proxy for expected utility, but as there is no other practical metric, it will have to suffice.) This provides us with a straightforward way of comparing various ways of producing food. For each food production method, we multiply the number of deaths by their probability and then multiply that number by whatever discounting rate seem to be appropriate based on our degree of confidence that those individuals are sentient—and so have interests, and so are worthy of moral consideration. For instance, suppose that it is 80% likely that 100 million insects would die per acre if we were to raise a particular crop and treat it with a standard insecticide, and we take the probability of insect sentience to be, say, 1%. Then, the expected deaths would be 800,000.

The next step is to find a way to compare the number of invertebrates affected by plant and insect production. One way to do this is to focus on yield. According to recent USDA numbers, soybean fields generate about 2,868 pounds of soybeans per acre source. A mealworm weighs about 100 mg, so it would take roughly 13 million mealworms to replace an acre of soybean production. (At least if we assess by weight. Mealworms are actually more protein- dense than soybeans, so if that is the metric, the numbers will come out somewhat differently. But the basic point will go through without this complication.) Suppose that we take the probability of mealworm sentience to be very low—say, 1%. In that case, it looks like trading mealworms for soybeans would give us an expected death rate of 130,000 individuals. Plant production, therefore, seems preferable. (For an argument along these lines, see Tomasik (2016).)

However, this overlooks an important part of the calculus: namely, pest management. Estimates of invertebrate abundance in agricultural contexts vary considerably, but suppose that there are, on average, 10 million invertebrates per acre at any given time. It takes anywhere from 90 to 150 d for soybeans to mature, and they might be sprayed every 10 d or so. Assume that it takes an average of 100 d for soybeans to reach maturity, that pest management strategies manage to kill even 13% of the population at any given time, and that we should stick with the standard low average probability of invertebrate sentience that we have been employing (1%). That is enough to get us parity: 130,000 expected deaths.

Of course, that is all very speculative, but it is worth noting that it is speculative in ways that are generally friendly to the defender of plant production. Ten million invertebrates per acre is a very modest estimate, and pest management strategies probably cause far more deaths. (Pearse (1946) estimates about 125 million invertebrates per acre in the Duke Forest. Sabrosky (1953) reports that a team found nearly 10,000 arthropods per square foot in a “scrub oak area” in Pennsylvania, which is over 400 million per acre. Menhinick (1962) counted approximately 26,500 invertebrates in 3.7 m3 test plots in Cornell’s apple orchards, which is about 107 million per acre. The lowest estimate I could find is due to Barratt et al. (2009), who found densities between 8 million and 40 million invertebrates per acre in New Zealand grasslands, depending on when they sampled relative to a burn. Surely there are important differences between soybean fields and these environments, but I am not aware of any data on total invertebrate populations in soybean fields, so these numbers have to be used as proxies.) Admittedly, insect production is not without waste. Mealworms get diseases and die en masse; crickets sometimes cannibalize one another; various species find ways to crush one another. In conversation, one farmer told me that you have done quite well if you have brought your loss rate down to 20%. So, we may need to increase the expected death count for mealworm production, but only by a relatively low percentage. We would not need to increase it by a factor of 10, which may well be what would be required to get a more realistic population estimate in fields where plants are grown for food. Finally, we should acknowledge that if insect farmers do not use recycled feed—e.g., spent grains from breweries, or the corn mash left over from ethanol production—then the scales would tip squarely in favor of plant production. In that case, we would have to count both the insects killed in the creation of the feed and the insects being raised for food. But of course, many insect farmers do use recycled feed, as it is far cheaper. The upshot here is that an expected death assessment does not come out squarely in favor of plant production and may well favor insect farming.

see the source. In another paper, the same author runs the numbers this way: Admittedly, we don’t have clear evidence for insect sentience. However, entomophagy would involve killing an extraordinarily large number of insects. So, given even very low odds, the expected utility of eating insects might be negative. For example, let’s estimate that 1000 clearly-sentient animals will die per acre as a result of standard agricultural practices. According to the most recent USDA numbers, the average soybean field yields about 2868 pounds of soybeans. A mealworm weighs about 100 milligrams, so it would take 13,009,000 mealworms to make up for that agricultural loss. So, even if we take the probability of mealworm sentience to be very low—say, 1 %—the expected utility calculation comes out in favor of soybeans, since we’d be comparing the loss of 1000 morally-relevant lives to the loss of 130,090 such lives. The upshot? We ought to maintain a strict vegan diet.

This expected utility calculation overlooks an important part of plant agriculture: pesticides. Estimates vary, but even the most conservative ones indicate that there are well over 100 million insects per acre, and others put the number over 400 million per acre (see, e.g., Sabrosky 1952 and Pearse 1946, respectively). Moreover, many of those insects are going to be affected by pesticides. But let’s just suppose that there are only 100 million insects per acre, and either (a) pesticides aren’t particularly effective or (b) the strict vegan only wants to hold on to the possibility that some portion of those beings are sentient. We might be left with, say, 20 % of the original number. Still, that’s 20 million insects that plant production harms. So, the comparison is not between the loss of 1000 morally-relevant lives to the loss of 130,090 such lives. Instead, it’s between the loss of 201,000 lives (1000 ? 1 % of 20,000,000) and 130,090. Eating insects wins.