80,000 Hours Podcast
#198 – Meghan Barrett on challenging our assumptions about insects
Episode guests
Podcast summary created with Snipd AI
Quick takeaways
- Insects exhibit varying levels of parental care, with some species, like termites, forming long-lasting monogamous pairs and nurturing their young.
- Research suggests that certain insect species experience pain and complex emotional states, indicating a level of sentience that warrants consideration for welfare standards.
- Understanding the biological classification of insects is crucial, as they are more closely related to crustaceans, affecting perceptions of their behavior and welfare.
- The diversity in insect body sizes, ranging from microscopic to larger than mice, challenges stereotypes and highlights the complexity within the insect world.
- Investigating insect cognitive abilities reveals that smaller brains can support complex behaviors, suggesting the need for nuanced criteria in assessing sentience across species.
- Insect farming has the potential to utilize agricultural waste sustainably, but it faces challenges related to disease management and ethical treatment of farmed insects.
Deep dives
Parental Investment in Insects
Contrary to common belief, not all insects lack parental investment in their young. While some insect species might lay a large number of eggs without providing care, others, such as certain termites and wood roaches, exhibit high levels of parental care, forming long-lasting monogamous pairs. For instance, termite queens and their mates can maintain their pair bond for up to 20 years, showcasing significant parental investment. In addition, queen ants are known to live for up to 30 years, highlighting that several insects possess both longevity and the capacity for parental care.
Sentience in Insects
The podcast explores the evolving view on insect sentience, highlighting compelling evidence that suggests some insect species experience pain. Researchers have demonstrated depression-like states in fruit flies, which can be affected by treatments that work on humans, indicating a complexity in their emotional responses. Additionally, genetically modified fruit flies that can perceive capsaicin as painful will avoid spicy food, showcasing a conscious decision-making process related to discomfort. These findings suggest that at least some insects possess a level of sentience that warrants further investigation and consideration for future welfare standards.
Defining Insects
A clear understanding of what constitutes an insect is essential for discussing their biology and welfare. Insects belong to the class Insecta, which is characterized by six legs, a chitinous exoskeleton, and distinct developmental stages. Interestingly, insects are more closely related to crustaceans than to other arthropods like spiders and centipedes, which are often mistakenly categorized as insects. Recognizing this evolutionary relationship can help shape our understanding of insect behavior, welfare, and potential sentience.
Diverse Body Sizes in Insects
Insect species exhibit a remarkable range of body sizes, with some individuals being microscopic while others can be larger than a mouse. Insects can vary by a factor of approximately 5.2 million in body mass, unlike vertebrates, which only vary by about 72,000 times. Giant insects like the Goliath beetle demonstrate this diversity, showcasing how perceptions of insects as universally small are misleading. This body size variation challenges common stereotypes and underscores the complexity of the insect world.
Brain Structure and Complexity
The relationship between brain size and sentience in insects is nuanced, challenging common assumptions that larger brains equate to greater complexity. Research indicates that smaller brains can produce complex behaviors, such as numerical cognition and social learning, seen in species like honeybees. Meanwhile, larger brains could reflect redundancies rather than advanced cognitive functions, suggesting that the quantity of neurons does not solely determine an organism's capacity for experience or sentience. This understanding emphasizes the need for careful criteria in evaluating cognitive abilities across different species.
Life History Strategies
The podcast discusses various life history strategies among insects, debunking the assumption that all insects produce numerous offspring with little investment. Some insects engage in live birth or exhibit substantial parental care, adjusting to environmental pressures and reproductive challenges. For example, certain flies nurture their young internally before birthing them, which contrasts the traditional view of insect reproduction. This complexity in reproductive strategies highlights the need to reevaluate how we understand insect development and their associated welfare needs.
Insect Behavior and Cognition
Insects display a wide range of complex behaviors typically underestimated due to their size and developmental strategies. These behaviors include numerical cognition, social learning, and even play in species like bumblebees and fruit flies. Some studies have shown that insects engage in tool use and can recognize faces, broadening the understanding of their cognitive capacities. This behavioral richness raises questions about their potential sentience and underscores the importance of further research into their welfare considerations.
Waste Stream Utilization
The potential benefits of insect farming include utilizing agricultural waste and reducing environmental impact. By rearing insects on food waste, the industry can minimize resource consumption while providing a sustainable source of protein. Furthermore, insects like black soldier flies are seen as valuable for their ability to convert organic waste into edible protein for livestock or humans. This innovative aspect of insect farming supports their promotion as a sustainable alternative to traditional livestock farming.
Predation and the Role of Disease
The farming of insects is not without its challenges, particularly concerning disease and predation. Insects can be susceptible to various diseases that affect their growth and reproduction, resulting in significant population losses. For example, the cricket paralysis virus severely impacts cricket populations, leading to concerns regarding welfare on farms. A full understanding of the diseases affecting different insect species is vital for improving their farming conditions and overall welfare.
Human Consumption and Insect Protein
The consumption of insects as food is gaining traction, particularly in Western countries as the industry grows and populations become more food-conscious. Although acceptance remains low, there is significant interest in protein-rich insects like crickets and mealworms that provide sustainable alternatives to traditional meat sources. However, much of the human consumption side of the industry relies on consumer behavior and perception. As educational efforts continue to promote the benefits of insect protein, society's views may shift further toward acceptance.
Ethical Challenges in Insect Farming
Insect farming introduces a host of ethical challenges that researchers and producers must navigate. Issues such as inhumane slaughter methods and the potential for diseases raise concerns about the welfare of farmed insects. As awareness of insect sentience grows, it becomes increasingly important to establish welfare standards that guide the industry toward more humane practices. Balancing production efficiency and ethical treatment remains a complex yet crucial aspect of the growing insect farming sector.
"This is a group of animals I think people are particularly unfamiliar with. They are especially poorly covered in our science curriculum; they are especially poorly understood, because people don’t spend as much time learning about them at museums; and they’re just harder to spend time with in a lot of ways, I think, for people. So people have pets that are vertebrates that they take care of across the taxonomic groups, and people get familiar with those from going to zoos and watching their behaviours there, and watching nature documentaries and more. But I think the insects are still really underappreciated, and that means that our intuitions are probably more likely to be wrong than with those other groups." —Meghan Barrett
In today’s episode, host Luisa Rodriguez speaks to Meghan Barrett — insect neurobiologist and physiologist at Indiana University Indianapolis and founding director of the Insect Welfare Research Society — about her work to understand insects’ potential capacity for suffering, and what that might mean for how humans currently farm and use insects. If you're interested in getting involved with this work, check out Meghan's recent blog post: I’m into insect welfare! What’s next?
Links to learn more, highlights, and full transcript.
They cover:
- The scale of potential insect suffering in the wild, on farms, and in labs.
- Examples from cutting-edge insect research, like how depression- and anxiety-like states can be induced in fruit flies and successfully treated with human antidepressants.
- How size bias might help explain why many people assume insects can’t feel pain.
- Practical solutions that Meghan’s team is working on to improve farmed insect welfare, such as standard operating procedures for more humane slaughter methods.
- Challenges facing the nascent field of insect welfare research, and where the main research gaps are.
- Meghan’s personal story of how she went from being sceptical of insect pain to working as an insect welfare scientist, and her advice for others who want to improve the lives of insects.
- And much more.
Chapters:
- Cold open (00:00:00)
- Luisa's intro (00:01:02)
- The interview begins (00:03:06)
- What is an insect? (00:03:22)
- Size diversity (00:07:24)
- How important is brain size for sentience? (00:11:27)
- Offspring, parental investment, and lifespan (00:19:00)
- Cognition and behaviour (00:23:23)
- The scale of insect suffering (00:27:01)
- Capacity to suffer (00:35:56)
- The empirical evidence for whether insects can feel pain (00:47:18)
- Nociceptors (01:00:02)
- Integrated nociception (01:08:39)
- Response to analgesia (01:16:17)
- Analgesia preference (01:25:57)
- Flexible self-protective behaviour (01:31:19)
- Motivational tradeoffs and associative learning (01:38:45)
- Results (01:43:31)
- Reasons to be sceptical (01:47:18)
- Meghan’s probability of sentience in insects (02:10:20)
- Views of the broader entomologist community (02:18:18)
- Insect farming (02:26:52)
- How much to worry about insect farming (02:40:56)
- Inhumane slaughter and disease in insect farms (02:44:45)
- Inadequate nutrition, density, and photophobia (02:53:50)
- Most humane ways to kill insects at home (03:01:33)
- Challenges in researching this (03:07:53)
- Most promising reforms (03:18:44)
- Why Meghan is hopeful about working with the industry (03:22:17)
- Careers (03:34:08)
- Insect Welfare Research Society (03:37:16)
- Luisa's outro (03:47:01)
Producer and editor: Keiran Harris
Audio engineering by Ben Cordell, Milo McGuire, Simon Monsour, and Dominic Armstrong
Additional content editing: Katy Moore and Luisa Rodriguez
Transcriptions: Katy Moore
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