Soil invertebrates are terrestrial invertebrates that spend most of their life in soil or litter. They influence nutrient cycling, plant growth, and carbon dynamics. Examples of soil invertebrates include soil ants, termites, springtails, mites, and nematodes. Each of these groups is much more numerous, and has many more neurons in total than wild vertebrates and farmed animals. Vasco Grilo has argued that overall changes in welfare may be determined by effects on soil invertebrates, even accounting for soil ants and termites only, instead of effects on the beneficiaries targeted by interventions. However, there is large uncertainty about the expected intensity of the subjective experiences of soil invertebrates, whether they have positive or negative welfare, and what increases or decreases their population. So Vasco advocated for more research informing how to increase the welfare of soil invertebrates over pursuing whatever land use change interventions naively seem to achieve that the most cost-effectively.