This post summarizes research into the Chinese mantis, focusing on the genes associated with nociception (the ability to perceive noxious stimuli). This type of research may help to improve the conditions on farms to better meet the needs of insects.

This is the third report in Rethink Priorities’ Shrimp Welfare Sequence, a series that addresses whether and how to best protect the welfare of shrimp. After outlining the welfare threats farmed shrimp may face, this report investigates the effect of these welfare threats on pre-slaughter mortality.

This post is a short summary of research on farmed cricket welfare considerations funded by Rethink Priorities as part of our research agenda on understanding the welfare of insects on farms. The paper includes recommendations.

This post is a short summary of research on yellow mealworm welfare that was funded by Rethink Priorities. The full paper on this research was published in a peer-reviewed, open access journal.

This is the second report in Rethink Priorities’ Shrimp Welfare Sequence. The first report estimated the scale of shrimp farming. This report examines the welfare threats that these individuals face.

Approximately 200-300 billion black soldier flies are farmed annually. In a new post, academic collaborator Meghan Barrett (Ph.D. Entomology) summarizes and provides additional context related to her and her colleagues’ academic article on “Welfare considerations for farming black soldier flies, Hermetia illucens (Diptera: Stratiomyidae): a model for the insects as food and feed industry.”

Voluntary certification schemes (VCS) specify production standards and auditing processes. International VCSs are one of the few current governance tools to improve the welfare of farmed fishes and shrimps. Knowing to what degree farmers register with certification schemes and what influences their decisions may inform future uses of this animal welfare advocacy strategy. This shallow literature review addresses the determinants considered by exporting farmers in China and Thailand.

This report is a postscript to "The relative Importance of the severity and duration of pain,” and addresses whether the order of negative and positive experiences matter. For example, is pain worse if it occurs at the end of an individual’s life?

How should effective altruists decide whether to prioritize interventions that alleviate severe but relatively brief suffering or instead those that alleviate longer-lasting but less severe suffering? When one pain is longer-lasting but less intense than a second pain, the most straightforward way to compare how much disutility they cause is to multiply how much longer by how much less severe the first pain is than the second pain. This report investigates whether this mathematical approach is sufficient for making cause prioritization decisions, requires some amendments, or is fundamentally flawed.

Billions of black soldier flies (BSFs) are farmed annually. This post summarizes research into the brain cell counts of BSFs, which may help us to assess the likelihood that they are sentient. The research described in this post was the first to use the isotropic fractionation technique to count an insect’s brain cells across developmental stages and the first to describe the nervous system of a popular, farmed invertebrate.

A significant share of Americans are uncertain (24%-45% don’t know) about their attitudes toward insect farming. This suggests that consumers may be particularly responsive to information on insect farming and that these views are largely “up for grabs”. There may be a large first mover advantage to whomever first ends up informing consumers most clearly. More Americans oppose a ballot measure to ban insect feed for farmed animals (49%) than support it (29%). We did find high levels of support (52%-65%) for the idea that insects (honeybees, ants, termites) were capable of feeling pain.

At least 420 billion to 1 trillion silkworms are killed annually to produce silk. While only 61 billion to 170 billion of these worms die due to diseases and pests, diseases cause up to 99% of the cumulative days of potentially negative experiences I identified on farms, (with the remaining 1% caused by slaughter). This suggests that research to inform the prioritization of the silk industry for animal advocates ought to focus on the sentience of silkworms, not pupating silk moths, as has usually been assumed. Campaigns to ban silk or stop its sale at retail locations are plausibly the most promising avenue for animal advocates to reduce silk production, therefore reducing the days of potentially negative experiences caused by diseases on silk farms. Developing and promoting alternative silks may also be promising as an intervention.

Currently, estimates of the number of invertebrates used or killed by humans are very poor. Summing the rigorous estimates that exist, at least 7.2 trillion to 26 trillion invertebrates annually are killed directly by humans, and 18 trillion to 40 trillion are used but not killed annually. I outline some of the largest invertebrate industries, and estimate the total number of invertebrates used or killed by humans. In total, not including nematodes, I believe between 100 trillion and 10 quadrillion invertebrates are directly killed or used annually by humans. The majority of this impact is caused by the application of agricultural pesticides.

Currently, 1 trillion to 1.2 trillion insects are raised on farms annually for food and animal feed. There are currently between 79 billion and 94 billion insects alive on farms globally on average on an average day. While it is unclear what welfare reforms might best improve the lives of insects on farms, it seems possible that standardized training on best practices, and potentially slaughter reform are promising ways to improve insect welfare on farms.

The number of snails produced for human consumption increases gradually every year. Still, there is very little awareness about the details of snail production or how serious an ethical problem it might be. In this report, I assess snail production and farming-specific welfare concerns, and discuss some scale, neglectedness, and tractability considerations.

Whether invertebrates have a capacity for valenced experience is still uncertain. Rethink Priorities has been systematically exploring this issue during the past months. Here, in the fourteenth post of this series, I explore our attitudes towards invertebrates, draw attention to different possibilities of ‘indirect advocacy’ and suggest some questions that deserve further research. As remarked in our previous post, even if we concluded that invertebrates are conscious and even if we had the means to help them, we would still need to determine how likely it is that specific interventions on their behalf will be supported and adopted. Future research on this matter will allow us to better determine the tractability of improving invertebrate welfare.

At any given time there are more than a trillion managed honey bees. Globally, the number of managed colonies has risen steadily over the last twenty years and this growth will almost certainly persist, at least in the short term. Increases in demand for honey and (especially) commercial pollination services continue to outpace the increase in supply of managed bees. Asia, especially China and India, hosts the largest populations of managed bees and accounts for much of the recent growth in bee stocks. Commercial beekeeping techniques standardly treat managed bees as a resource from which to maximize the extraction of value. Beekeepers have a financial incentive to maintain the health of their colonies, but they have little reason to look after the welfare of individual bees. Managed bees suffer from a variety of problems, including pesticide exposure, poor nutrition due to inadequate access to natural forage, invasive hive inspections and honey harvest, stress from long-distance transport, and parasite and pathogen spread exacerbated by common management techniques.

Whether invertebrates possess the capacity to have valenced experiences is still uncertain. On the assumption that invertebrate welfare is a relevant cause area, we explore here different possibilities of assisting invertebrates, both those living in the wild and those under human control. When possible, specific interventions to reduce invertebrate suffering are presented. In other cases, I suggest which questions should be further investigated in order to better understand the problem and to study feasible intervention strategies.

Whether invertebrates have a capacity for valenced experience is still uncertain. Given that uncertainty, we argue that supporting the cause of invertebrate welfare means, at present, promoting additional research. To that end, we explore and outline key research questions in two areas: (i) invertebrate sentience and (ii) philosophical research into consciousness. Regarding the first, we propose further research on those features which, according to expert agreement, seem to be necessary for consciousness (e.g., nociceptors and centralized information-processing structures). We also suggest looking into the quality of invertebrates’ lives. Finally, concerning philosophical research into consciousness, we suggest that the inherent difficulties in the detection of morally significant pain and pleasure in nonhumans should be further investigated. We also highlight other more specific problems about phenomenal consciousness and its moral implications.

In this post, four members of Rethink Priorities’ invertebrates team—Daniela R. Waldhorn, Marcus A. Davis, Peter Hurford, and Jason Schukraft—outline their views on the value, feasibility, and danger of quantitative estimates of invertebrate sentience. Marcus and Peter provide numerical estimates of sentience for each of the taxa we investigated for our invertebrate sentience project, Daniela offers a qualitative ranking of the same taxa, and Jason argues that we are not yet in a position to deliver estimates that are actionable and robust enough to outweigh the (slight but non-negligible) harm that publishing such estimates prematurely might engender.