Given uncertainty about insect sentience, the welfare implications of different killing methods for farmed insects deserve consideration, particularly at the scale of billions of individuals.
Insect killing method welfare is a genuinely uncertain domain where precautionary reasoning justifies preferring methods that minimize potential suffering even without certainty of sentience. The three-layer approach — applying welfare consideration proportional to evidence of sentience — suggests that at the scale of billions of insects killed daily, the potential aggregate suffering from aversive killing methods justifies choosing less aversive alternatives when cost differences are small. Cold immobilization before grinding or hot water killing would eliminate the most clear welfare concern — grinding or scalding of potentially sensate animals. The insect welfare field is developing rapidly, and guidance on preferred killing methods based on emerging evidence about insect pain processing will become more specific as the science advances.