EA - Demodex mites: Large and neglected group of wild animals by Mai T

Link to original articleWelcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Demodex mites: Large and neglected group of wild animals, published by Mai T on January 27, 2023 on The Effective Altruism Forum.Content warningThis article contains information about the human body that some readers may find uncomfortable. There is nothing graphic, but there is detailed information about a genus of human parasites.SummaryDemodex mites are arachnids who live their entire life cycle on/in human skin. Basically every human seems to have numerous mites living on them. Rough estimates suggest that there could be thousands or even millions mites living on each human face, meaning trillions living on all human faces.It seems likely that Demodex mites are frequently killed by human activities, including bathing, tattoos, the use of light therapy, the use of some medicines, and possibly makeup (though I wasn't able to confirm the effects of makeup with experts).Given the scale and neglectedness, this may make Demodex mites a potentially impactful focus for future animal advocacy strategy (though perhaps less impactful than other wild invertebrate interventions). This could be relevant for EAs and researchers interested in wild animal suffering. The first step would be to do a bit more research on some key uncertainties.It's unclear whether Demodex mites are sentient because nobody has researched this question. Given evidence of sentience in other groups of invertebrates and the immense number of Demodex mites who are alive at any one time, it seems plausible that we should be giving serious consideration to their interests.Research direction: A literature review on arachnid sentience, in the style of Gibbons et al (2022), would be helpful here.Another uncertainty is whether Demodex mites are on parts of the bodies that have not been well-sampled in scientific studies (e.g. arms, hands, legs, stomach).Research direction: It would be quite easy to resolve this using a lens that you can buy for ~$420 USD plus your smartphone. This could be a great little project for a small team of volunteers, like a university EA group.Beyond the implications for animal advocacy movement strategy, Demodex mites may also have implications for the ethics of personal lifestyles. I'm updating in the following ways: I will no longer conduct activities that could kill Demodex mites that I do purely for pleasure (for me, this includes tattoos on my head and upper body, and maybe face makeup). I will continue to do essential activities like bathing and receiving health treatments (e.g. laser therapy, antibiotics) despite the possibility that doing so will kill Demodex mites.You may or may not want to do anything about this. After all, many human activities similarly affect the lives of invertebrates (e.g. driving, composting food, gardening, sanitation).I know having concern for the interests of skin mites might seem pretty wild to many people. To me, trying not to kill Demodex mites seems comparable to trying not to step on ants when it can be avoided, which is something that many people (particularly EAs and animal advocates) find sensible. Obviously, this hinges on one's beliefs about the moral value of mites, compared to other animals.Demodex mitesWhat are they?Demodex mites are arachnids who live on and in human skin.There are two main species that live on humans: Demodex folliculorum and D. brevis. There are other species that live on other animals.How common are they?It is very plausible that 100% of humans have Demodex mites (other than newborn babies).Many studies that have recorded prevalences around 20-80% using visual identification methods.But one study found genetic evidence of Demodex mites in 100% of humans participating in the study.There are two possible explanations: genetic sampling is better than visual identification, so ~100% of humans have...