Do insects feel pain?

The objection

“Insects are basically tiny robots. Farming them for protein gives you guilt-free meat, because they don’t feel anything.”

The answer

Entomologists long assumed that insects could not feel pain, and that view helped keep them out of animal welfare law [1]. The assumption has now been tested with the method that persuaded the UK to recognise crabs and lobsters as sentient, and several insect orders came out level with them or ahead.

How strong is the evidence that insects feel pain?

The evidence is strong for adult flies and cockroaches, which score higher than the crabs and lobsters UK law already treats as sentient. In 2021 Jonathan Birch of the London School of Economics and four co-authors weighed more than 300 studies for the UK’s environment department, Defra, and recommended that all decapod crustaceans and cephalopod molluscs be regarded as sentient [2]. The Animal Welfare (Sentience) Act 2022 then brought every decapod and cephalopod, from crabs and lobsters to octopuses, into its definition of an animal; insects stayed out, though ministers can add other invertebrates by regulations [3]. In a 2022 paper setting out the framework’s eight neural and behavioural criteria, Andrew Crump and colleagues found that true crabs met five and lobsters and crayfish three [4]. That same year Matilda Gibbons and five colleagues, Birch among them, applied the criteria to six insect orders [1]. Adult flies and mosquitoes, and cockroaches and termites, met six, which the framework counts as strong evidence, and most other adult orders met three or four [1]: bees, wasps and ants four, and butterflies, moths, crickets and grasshoppers three [5].

Bumblebees show what the behavioural evidence looks like. In a 2022 experiment by Gibbons and colleagues, bees choosing between plain feeders and feeders heated to 55°C avoided the heated ones while the plain ones held rich sugar water, then fed from the heated ones more and more as the sugar in the plain feeders was reduced [6]. They told the feeders apart by colours they had learned, so the heat was being weighed against the sugar in the brain [6]. The 2022 review found no good evidence that any insect failed a criterion, so low scores, such as the two met by beetles, mostly mark experiments nobody has yet done [1][5]. The New York Declaration on Animal Consciousness, launched at New York University in 2024, places insects among the animals with at least a realistic possibility of conscious experience, and says “it is irresponsible to ignore that possibility in decisions affecting that animal” [7].

Do farmed insects feel pain?

Farmed black soldier fly larvae may well feel pain, though for mealworms the evidence is thin. Both are farmed and killed as larvae [8], and young insects are where the 2022 review found its biggest gaps [1]. Juvenile flies still met three or four criteria, which the framework counts as substantial evidence [1]. Mealworms are beetle larvae, and juvenile beetles were not among the young insects the review found meeting three or four, a gap that reflects missing studies, since no insect was found to fail a criterion [1]. Gibbons and colleagues, writing about the review in 2022, list extreme heat and cold, often after starvation, among the routine ways farmed insects are killed [5].

Would eating insects instead of meat reduce suffering?

Switching from meat to insects would probably mean far more animals farmed and killed, since black soldier fly larvae and mealworms alone are already estimated to outnumber the broiler chickens slaughtered each year. In a 2025 report forecasting farmed animal numbers, Rethink Priorities, a US research nonprofit, estimated that about 472 billion of these larvae were killed on farms in 2022, against about 76 billion broiler chickens slaughtered in 2023 [8]. The estimate is uncertain: its 90% credible interval runs from 51 billion, below the chicken figure, to 2.6 trillion, and the forecast for 2033 is nearly 5 trillion insects a year, with a range of 1.8 to 17.3 trillion [8]. For now, most farmed insects are not replacing meat on anyone’s plate. Much of the investment has gone into feed for pets, aquaculture, pigs and chickens, and producers currently sell mainly to the pet food market [8].