Background/Question/Methods The culture of global society commonly associates the word animal with vertebrates. Paradoxically, most of animal diversity is composed of small organisms that remain invisible in the global culture and are underrepresented in philosophy, science, and education. Twenty-first century science has revealed that many invertebrates have consciousness and the capacity to feel pain. These discoveries urge animal ethicists to be more inclusive and to revaluate the participation of invertebrates in the moral community. Science also has warned of the disappearance of small animal co-inhabitants that is occurring in the midst of the sixth mass extinction. This “invisible extinction” compels environmental philosophers to make visible invertebrates, whose existence is precious in itself and for the functioning of ecosystems on which biodiversity and human societies depend. To investigate the roots of modern taxonomic chauvinism, and opportunities to overcome it, I used my “3Hs” model of the biocultural ethic that values the vital links among co-in-Habitants, their Habits, and shared Habitats, to examine how animals are represented in: (i) the work of David Hume (whose empiricist philosophy had a seminal influence on Charles Darwin’s evolutionary thinking); (ii) Darwin’s notes on Hume, and (iii) traditional ecological worldviews. Results/Conclusions In Hume's complete works, I found 526 mentions of animals. Among them, 97% correspond to vertebrates, and only 3% to invertebrates. This marked taxonomic bias toward vertebrates evokes a mirror image of animal diversity in the biosphere, because 97% of the animal species described by science are invertebrates, and only 3% are vertebrates. However, Hume’s disproportionate mammal-centric taxonomic bias is counterbalanced by two key concepts: (i) invertebrates have sentient processes and are “guided by reason” in a manner comparable to vertebrates; (ii) the world might have been generated and not created. Inspired by Hume, Darwin concluded that the same generation process “applies to the entire animal kingdom.” Using my “3Hs” (Habitat, Habits, co-in-Habitants) model of the biocultural ethic, I identified concepts in philosophy, sciences, and also indigenous worldviews that help us to overcome taxonomic chauvinism by understanding the interrelationships among humans and other animals as co-constituting their life habits and shared habitats. The understanding that we share habitats with vertebrates, invertebrates, and multitude of other beings has ontological, epistemological, and ethical implications for overcoming taxonomic chauvinism and (re-)valuing small co-inhabitants who are precious in themselves and essential to the functioning of the global biosphere and the well-being of human societies.