Scientific research on animal sentience has expanded dramatically in recent decades, with major findings across taxa that are reshaping our understanding of which animals merit moral consideration.
Sentience research is the scientific foundation of animal welfare. Understanding which animals can experience suffering — and how intensely — is essential for calibrating moral responses. Recent decades have dramatically expanded the circle of animals considered likely sentient, adding fish, crustaceans, and potentially some insects to earlier certainty about mammals and birds. This expanding circle demands an expanding circle of moral concern.