The science of animal sentience has advanced dramatically in recent decades, with implications for how we understand and respond to animal welfare across species.
As sentience science advances, the circle of moral consideration expands to include more species at greater scales. The recognition that fish experience pain and stress has implications for billions of farmed fish killed annually with no welfare consideration. The inclusion of decapod crustaceans in UK sentience law reflects a regulatory response to scientific evidence. Research into invertebrate sentience is ongoing and may reveal suffering across an even broader range of species. The scientific understanding of animal sentience provides the foundation for evidence-based welfare policy that can reduce suffering at massive scale.