Invertebrate Welfare — June 2020
Insects farmed for food and feed
With Rethink Priorities, I’ve just published the first comprehensive review of the insect protein farming industry. The report covers the scale of insect farming, common practices on farms, slaughter methods, causes of pre-slaughter mortality, and the legal policies governing the sale and consumption of insects. Some key takeaways:
The industry farms over a trillion insects annually, and I expect this number to increase dramatically over the next ten years as large-scale production facilities funded in the last few years get started and scale up.
The largest addressable causes of pre-slaughter mortality seem to be introducing better rearing practices, such as using better water storage containers in farms.
While I am not certain about the painfulness of different slaughter methods, the limited evidence available appears to indicate that rapid shredding is the most humane method.
Information on sub-lethal welfare issues on insect farms is extremely limited and speculative.
The industry sees the greatest potential for growth in the use of insects as animal feed, not as human food.
Invertebrate welfare
A new study in Current Biology found that high protein diets may help caterpillars and other insects fight blood parasites, which seems like a plausible welfare benefit.
In Animal Sentience, veterinarians raised objections and issues with individualistic approaches to invertebrate welfare, in response to an article arguing to extend moral personhood to invertebrates.
The first objection is that the sheer number of invertebrates may make it difficult to take a consequentialist approach to their welfare. This contrasts with the reaction some animal advocates have toward insect numbers, seeing the magnitude of insect populations as a reason to prioritize invertebrates.
Their second objection is that because some insects go through holometabolic metamorphosis, it is plausible that a different individual emerges, complicating ethical calculus. They state that, “one could… argue that preventing larvae from reaching their ‘higher self’ adds an extra dimension of harm that an individualistic ethical theory cannot straightforwardly capture.”
I find these comments interesting, though I don’t know what to make of them. I personally am less concerned about the loss of potential individuals than harms to currently existing ones.
However, I do think that it’s possible that larval and adult insects have very different kinds of experiences, and are different individuals in some meaningful sense, complicating a direct comparison between mealworm and cricket farming, for example.
Their third objection is that eusocial insects might count as less than an individual, citing a study on wasp sociality and cognition, and that supraorganismal colonies might be individuals themselves, “Supraorganismal colonies therefore exhibit a behavioural and physiological range that surpasses that of the individuals, and there is a clear sense in which the colonies themselves have a welfare of their own, in that they have interests that determine whether things go better or worse for them.”
This, if true, doesn’t seem necessarily to mean that insect lives are worse less, but that colonies ought to be valued as the sum total of the insect’s welfare plus the welfare of the colony itself.
See “If materialism is true, the United States is probably conscious,” which is either insightful or a good demonstration that this kind of argument is on a slippery slope.
Miscellaneous
A study found that lasering sea lice off of salmon doesn’t seem to work, but it also doesn’t seem to hurt salmon.
Lasers are regularly used for treating sea lice, and it seems plausible they are more humane than alternatives, like acid treatments that are harmful to both the lice and the salmon, so it is unfortunate that this approach may not be effective (unless the parasitic relationship leads to a net positive welfare value, in which case, go lasers go).
Cockroach milk sounds like a really bad superfood, but okay.