Emerging research on invertebrate sentience is challenging the assumption that insects and other small animals do not experience pain or suffering, with major implications for animal welfare.
The precautionary principle suggests we should extend moral consideration to animals where evidence of sentience is plausible even if not proven beyond doubt. For insects, the evidence is increasingly supportive of nociception and possibly affective states. Given the astronomical numbers involved — in agriculture, pest control, and research — even small probabilities of suffering across insect populations represent potentially vast amounts of negative experience. Invertebrate welfare is one of the most rapidly growing areas of animal welfare science.