Global insect production for food, feed, and biowaste processing is growing rapidly. Black soldier fly (Hermetia illucens), mealworm (Tenebrio molitor), and house cricket (Acheta domesticus) are primary farmed species. Estimates suggest hundreds of billions to trillions of insects are farmed annually worldwide.
Insects have central nervous systems with approximately 1 million neurons (compared to 86 billion in humans). They have nociceptors and produce endogenous opioids. Behavioral evidence shows aversive learning and wound-related protective behavior. The scientific debate centers on whether these responses involve subjective suffering or are purely reflexive.
Research by Rethink Priorities (Muehlhauser, Sebo, others) applies a probability-weighted framework to insect sentience. Even a small probability of sentience at scale creates large moral implications. The analysis has influenced policymakers in Switzerland, UK, and New Zealand to consider insect welfare in legislation.
Current farming practices — extremely high density, limited environmental complexity, processing methods (milling, boiling, freezing, CO2 stunning) — would be major welfare concerns if insects are sentient. Density levels in insect farms are orders of magnitude higher than any vertebrate farming system.
The most welfare-relevant insect farming question may be slaughter method. Cold stunning (chilling below 4°C) causes torpor before killing. Boiling, grinding, and freezing without prior stunning are common industry practices. Research is beginning to evaluate which methods minimize suffering given uncertainty about insect sentience.
Switzerland added cephalopods and decapod crustaceans to its Animal Welfare Act; insects are not yet included. The UK Animal Welfare (Sentience) Act 2022 covers decapod crustaceans. Insects remain outside most national animal welfare legislation. The European Food Safety Authority (EFSA) has called for more research before regulatory conclusions.