Earthworms, nematodes, and other soil invertebrates are among the most numerous animals on earth. Emerging welfare debates ask whether their numbers and potential sentience warrant moral consideration.
Soil invertebrate welfare represents the frontier of animal ethics. The question of whether earthworms or nematodes experience anything like pain or suffering is genuinely unresolved, but the scale of their numbers and the magnitude of human impacts on soil ecosystems make the question worth taking seriously. Agricultural practices that degrade soil — particularly deep tillage and pesticide overuse — kill enormous numbers of invertebrates. Regenerative and no-till farming approaches that protect soil biology have welfare and ecological co-benefits. Even under significant uncertainty about invertebrate sentience, practices that avoid unnecessary soil disturbance represent a reasonable precautionary approach with demonstrable ecological benefits.