Insect farming is booming. But is it cruel?

Insects are strange, wondrous beings. Butterflies can see parts of the light spectrum that are invisible to human eyes and use these ultraviolet patterns to find their way to tasty plants. Moths use the Earth’s magnetic field to orient themselves on journeys of hundreds of miles. Bees waggle their butts to tell their hive-mates where to find a juicy stash of nectar. Insects live in our world—or humans live in theirs—yet we inhabit completely different sensory universes.

But just as we are starting to understand insect senses, something is shifting in the way we treat these creatures. Insect farming is booming in a major way. By one estimate, between 1 trillion and 1.2 trillion insects are raised on farms each year as companies race to find a high-protein, low-carbon way to feed animals and humans. In terms of sheer numbers of animals impacted, this is a transformation of a speed and scale that we’ve never seen before.

It’s a weird twist in our already strange relationship with bugs. We squash them, spray them, eat them, and crush them to make pretty dyes. But we also fret about plummeting wild insect populations and rely on them to pollinate the crops we eat. And with the industrialization of insect farming, bugs are being offered up as a solution to the human-caused climate crisis. But before we go down that route, we need to ask some really basic questions about insects. Can they feel? And if so, what should we do about it?

We’re at the starting point of a conversation about insect welfare,” says Jonathan Birch, a philosopher at the London School of Economics. One of the key questions here is whether insects are sentient and have the capacity to feel pain and suffer. Pigs, chickens, and fish are already widely recognized as sentient. In 2021, Birch wrote a report that led to the UK government recognizing sentience in squid and octopuses, as well as crabs, lobsters, and all vertebrate animals. Research on insect sentience is much more patchy. There are more than a million known insect species and only a handful have ever been studied to see whether they can feel pain.

Finding out whether another being can feel pain is really difficult, even when it comes to humans. Until the mid-1980s babies in the US were routinely operated on with little or no anesthesia, due to the mistaken belief that very young infants were incapable of perceiving pain. In one famous case, a premature baby in Maryland born in 1985 underwent open heart surgery without any anesthesia at all. When Jill Lawson, the boy’s mother, later questioned her doctors, she was told that premature babies couldn’t feel pain—a scientific misunderstanding that was later overturned partly thanks to the campaigning of people like Lawson.

If scientists can misunderstand pain in humans for so long, what hope do we have in figuring it out in insects? When searching for answers, there are a handful of signs researchers look for. One is the presence of nociceptors—neurons that respond to painful stimuli from the outside world. Nociception isn’t quite the same as feeling pain. When you touch a hot stove, your arm automatically jerks away before you feel pain, because nociceptors have sent a nerve impulse that bypasses the brain altogether. But at the very minimum, the presence of nociceptors indicates that a bug has some of the basic biology that makes it capable of experiencing pain.

Almost every time scientists search for insect nociception, they find it, says Lars Chittka, founder of the Research Centre for Psychology at Queen Mary University of London and author of The Mind of a Bee. There’s evidence for nociception in beetles, flies, bees, and butterflies. We also have good evidence that at least some insects can bring together sensory information in their brains, and that their nociceptors are connected to their brains. Plus, scientists have seen some evidence of insects grooming injured spots on their bodies—another indication of sentience. Some ants even rescue nestmates that have lost limbs after raids on termite mounds. Wound-tending is generally seen as a sentience marker.

For Chittka, the fact that scientists have found multiple indicators of sentience in certain insects is reason enough to argue that these animals can have unpleasant experiences. Chittka puts flies and bees in this category, but it’s not at all clear whether findings can be extrapolated to other species. The most commonly farmed insects include crickets, beetles, and flies, and we know a lot less about their lives than those of bees or ants, which are pretty well-studied in insect terms. Even fewer studies have been done on insects when they’re still larvae. This adds another problem because mealworms and black soldier fly larvae are usually killed before they are adults. Are insect larvae less capable of feeling pain than adults? We really don’t know.

It’s also about widening our sense of which animals deserve our compassion. It’s easy to look into the eyes of a dog, or a chimp, and intuit that these animals have feelings that we can influence. It’s much more difficult to look upon a tray of mealworms and make the same observation. If we’re going to start farming these animals en masse, though, the kindest thing to do might be to err on the side of caution.