Research on invertebrate welfare is advancing rapidly. Understanding the current evidence base and its implications for policy helps advocates engage with this emerging and important area.
The exclusion of most invertebrates from animal welfare legislation reflects the current state of scientific uncertainty rather than certainty of their insensitivity. The more invertebrate welfare research is conducted, the more evidence accumulates that at least some invertebrates have nociceptive systems and behavioural indicators of pain and distress. The policy implications of extending welfare concern to even a fraction of invertebrate species would be transformative — insect welfare alone, given agricultural insect populations, would represent one of the largest welfare issues in the world. The precautionary principle — extended to invertebrates — would radically expand the scope of animal welfare concern.