Much of the recent hubbub about eating bugs has stemmed from the discovery that farming insects might be far more sustainable than raising conventional livestock. But that’s only part of entomophagy’s appeal: some experts say that in addition to their ecological advantages, insects also benefit from ethical ones. Raising and eating insects, they say, raises far fewer concerns about animal welfare than producing other kinds of meat.
For instance, one of the reasons cows, pigs and chickens suffer on so many factory farms is that they live out their days in unimaginably cramped conditions, with little personal space or freedom to roam. But in the wild, many species of insects already live in large groups and at high densities.
“Insects naturally live in close quarters,” says Laura D’Asaro, the co-founder of Six Foods, an American start-up that is manufacturing chips [crisps] made with cricket flour. “So insect farming makes sense in a way that is much more natural than [farming] traditional livestock. It makes more sense and it seems much more humane.”
However, it’s difficult to assess the ethics of insect farming as long as scientists remain in the dark about one crucial question: do insects feel pain?
In animals, pain detection begins with nociceptors, specialised receptors on nerve cells that are capable of sensing environmental stimuli that might cause bodily harm (e.g. extreme heat, cold or pressure). The nociceptors pass nerve signals to the spinal cord, brainstem and several other regions of the brain. These messages may trigger a reflexive response designed to help an organism avoid further injury – by, say, quickly pulling away a hand or a paw from an open flame.
Although insects’ capacity to experience pain has not been well studied, scientists have documented that at least some species do possess nociceptors and are capable of detecting, and responding to, potentially dangerous stimuli. For instance, when fruit-fly larvae feel a soldering iron press up against their bodies, they display defensive behaviour and quickly roll away.
But nociception, or the sensory detection of ‘noxious stimuli’, is different to pain, which is the subjective, emotional experience that often follows.
In mammals, at least, this pain experience relies on the cerebral cortex – the top, wrinkled layer of the brain responsible for high-level information processing and cognition. Nociception, by contrast, requires only lower-level brain areas, as well as the spinal cord and the peripheral nervous system.
The two processes are complementary, but distinct. For instance, cats and rats whose spinal cords have been severed – and thus feel no subjective pain – can still exhibit withdrawal reflexes in the face of dangerous stimuli. The rolling response of fruit-fly larvae may be similarly reflexive and does not necessarily indicate that the insects consciously experience pain. Insects’ nervous systems are hugely different to our own, and scientists simply don’t know whether they possess the requisite neurological machinery.
But because we aren’t certain, entomologists suggest we should give the organisms the benefit of the doubt and end their lives humanely. Unfortunately, some types of chemical euthanasia or anaesthetics may prove infeasible for animals destined for the food system, and there is still disagreement about which of the other methods – from freezing to shredding – might be the most kind. As with almost all the issues surrounding the use of insects as food, there’s a lot left to learn.