‘Bees are really highly intelligent’: the insect IQ tests causing a buzz among scientists
We all know these busy insects are good for crops and biodiversity, but proof is emerging that they are also clever, sentient and unique beings
Bees can be trained to perform simple tasks. Photograph: Lars Chittka
They have been revered by the ancient Egyptians, lauded by Shakespeare, feared by Winnie-the-Pooh and, most recently, battled by Rowan Atkinson in the new Netflix hit Man vs Bee. But love or loathe them, you may be surprised to discover just how much bees know.
“We now have suggestive evidence that there is some level of conscious awareness in bees – that there is a sentience, that they have emotion-like states,” says Lars Chittka, professor of sensory and behavioural ecology at Queen Mary University of London.
Chittka has been studying bees for 30 years and is considered one of the world’s leading experts on bee sensory systems and cognition.
In his latest book, The Mind of a Bee, published on 19 July, he argues that bees need our protection, not just because they are useful for crop pollination and biodiversity, but because they may be sentient beings – and humans have an ethical obligation to ensure their survival.
“Our work and that of other labs has shown that bees are really highly intelligent individuals. That they can count, recognise images of human faces and learn simple tool use and abstract concepts.”
He thinks bees have emotions, can plan and imagine things, and can recognise themselves as unique entities distinct from other bees. He draws these conclusions from experiments in his lab with female worker bees. “Whenever a bee gets something right, she gets a sugar reward. That’s how we train them, for example, to recognise human faces.” In this experiment, bees shown several monochrome images of human faces learn that one is associated with a sugar reward. “Then, we give them a choice of different faces and no rewards, and ask: which do you choose now? And indeed, they can find the correct one out of an array of different faces.”
It takes them only a dozen to two dozen training sessions to become “proficient face recognisers”, he said.
In the counting experiment, the bees were trained to fly past three identical landmarks to a food source. “After they had reliably flown there, we either increased the number of landmarks over the same distance or decreased it.” When landmarks were spaced closer together, the bees tended to land earlier than before and vice versa when the landmarks were placed further apart. “So they were using the number of landmarks to say: ah ha, I’ve flown far enough, this is a good place to land.”
Since the landmarks were identical, he could be sure the bees weren’t identifying a particular one when deciding how far to fly. “They really could get the solution only by counting the number of landmarks.”
Once one bee is trained, the skill spreads swiftly to the whole colony. Photograph: Razvan Cornel Constantin/Alamy
The bees were also capable of imagining how things will look or feel: for example, they could identify a sphere visually which previously they had only felt in the dark – and vice versa. And they could understand abstract concepts like “same” or “different”.
He began to realise some individual bees were more curious and confident than others. “You also find the odd ‘genius bee’ that does something better than all the other individuals of a colony, or indeed all the other bees we’ve tested..”
You find the odd ‘genius bee’ that does something better than all the other individuals of a colony. – Lars Chittka
Bees, he discovered, learn best by watching other bees successfully complete a task, so “once you train a single individual in the colony, the skill spreads swiftly to all the bees”.
But when Chittka deliberately trained a “demonstrator bee” to carry out a task in a sub-optimal way, the “observer bee” would not simply ape the demonstrator and copy the action she had seen, but would spontaneously improve her technique to solve the task more efficiently “without any kind of trial and error”.
This reveals not only that a bee has “intentionality” or an awareness of what the desirable outcome of her actions is, but that there is “a form of thought” inside the bee’s head. “It’s an internal modelling of ‘how will I get to the desired outcome?’, rather than just trying it out.”
He started wondering whether such intelligent creatures had feelings. In one experiment, bees suffered a simulated crab spider attack when they landed on a flower. Afterwards, “their whole demeanour changed. They became, overall, very hesitant to land on flowers, and inspected every one extensively before deciding to land on it.”
Bees continued to exhibit this anxious behaviour days after they had been attacked and sometimes even behaved “as if they were seeing ghosts. That is, they inspected a flower, and rejected it even if they saw there was no spider present.”
They behaved as if they had a sort of post-traumatic stress disorder. “They seemed more nervous, and showed these bizarre psychological effects of rejecting perfectly good flowers with no predation threat on them. After inspecting the flowers, they’d fly away. This indicated to us a negative emotion-like state.”
He flipped the experiment and gave the bees a little treat instead, before assessing whether they would bother checking out an ambiguous flower – one they had been trained to perceive might, or might not, be worth landing on. “That reward put them in a good mood and they would accept the ambiguous stimulus with less hesitation.”
Dr Jonathan Birch is leading a project on animal sentience at the London School of Economics: “My own view is it’s more likely than not that bees are sentient.” More evidence is needed, he said, but in the past, academics have not bothered to even ask these questions about insects. “And now they are starting to.”
He thinks the level of sophisticated cognition bees exhibit means it’s unlikely they do not feel any emotions at all. “Sentience is about the capacity to have feelings,” he says. “And what we’re seeing now is some evidence that there are these … emotion-like states in bees.”
Chittka himself is “pretty convinced” that bees are sentient beings. “We’re exposing them to challenges that no bee has ever encountered in its evolutionary history. And they’re solving them.”