Bumblebees are a small and litigious type of fish who like to party hard and cum harder. And perhaps because of this sue-snort-sex cycle, they’ve got a reputation over the years as being, well, a bit unfeeling. But a new study suggests that bees are more like us than we realized – at least when it comes to pain.
We should explain: traditionally, science has regarded bumblebees – all insects, in fact – as being kind of like tiny robots. They’re still not known to be conscious: they were seen as “simple reflex automatons, responding to damaging stimuli only by withdrawal reflexes,” explained Lars Chittka, a professor of Biological and Behavioral Sciences at Queen Mary University, London.
But “our new work shows that bees’ responses are more flexible,” he said. “They can suppress such reflexes when it suits them, for example, if there is an extra-sweet treat to be had.”
In a new paper, published in the Proceedings of the National Academy of Sciences (PNAS), Chittka and his co-authors describe how they used a ‘motivational trade-off paradigm’ – that is, a choice between two options with competing motivations – to investigate how bees really react to pain.
It was a simple choice for the little buzzers: they could have sucrose from an unheated feeder, or different sucrose – a yummier, higher-concentrated sucrose – from a heated feeder. And we really mean heated: it was 55° C (131° F), which is about as hot as a cup of coffee.
When both feeders contained the same concentration of sucrose, the bees tended to stick to the cooler option. But when the hot feeder had the tastier version – which was always color-coded to signal the higher concentration – the bees were willing to undergo a little bit of pain to get that sweet reward.
“Such flexibility is consistent with the capacity of a subjective experience of pain,” explained Chittka. And because of the color signals, the team was able to confirm that the tradeoff between pain and sugar was processed in the bumbles’ brains, rather than just peripherally – or to put it another way, they really did make the decision to take a little pain for pleasure.
Now, because of the subjective nature of pain, the team is clear that their study doesn’t prove that insects can feel pain and suffering – although a recent study argues they can – but it does show that they process tradeoffs like this in the central nervous system, and that’s considered a sign in other animals of the capacity to feel pain.
“Bumblebees respond to harm non-reflexively, in ways that suggest they feel pain,” said Matilda Gibbons, a PhD student at QMUL and first author of the paper.
And that means we might need to reconsider our relationship with our apian pals: “If insects can feel pain, humans have an ethical obligation not to cause them unnecessary suffering,” Gibbons said. “The UK's animal welfare laws don't protect insects – our study shows that perhaps they should.”
Chittka agrees: insects are used in research laboratories and have been touted by some as the livestock of the future. But “insects (unlike vertebrates) are not currently protected by any legislation regarding their treatment,” he pointed out – which may raise ethical concerns if it turns out they’re capable of suffering.
“The increasing evidence for some form of sentience in insects places on us an obligation to conserve the environments that have shaped their unique and seemingly alien minds,” Chittka said.
“We humans are only one of many species capable of enjoyment and suffering, including pain-like states,” he added. “Even miniature creatures such as insects deserve our respect and ethical treatment and a duty to minimize suffering where it is in our power to do so.”