The next step was to see whether these trained bumblebees could teach others their peculiar trick. Three bumblebees were selected as ‘teachers’. New, untrained bumblebees were placed with them in a small transparent cage close to the flowers to watch and learn. Fifteen of the 25 ‘pupils’ grasped the point by watching how their teacher did it, and they too managed to pull out their reward when they got to have a go afterwards. All in all, this experiment showed both that the bumblebees could learn this rather unnatural skill and that they were capable of teaching the strategy to others.
Clever Horse Hans and the Even Cleverer Bee
Hans the Horse of Germany was a global celebrity in the early 1900s. He couldn’t just count, he could also calculate – or so people thought. The horse could add, subtract, multiply and divide. He answered arithmetic problems by banging out the correct answer with his foreleg, and his owner, maths teacher Wilhelm von Osten, was convinced that the animal was just as clever as himself. In the end, it turned out that Hans couldn’t calculate at all or even count. That said, he was a whiz at reading the minuscule signals in his questioner’s body language and facial expressions. The person setting the problem had to count too, to make sure that Hans was giving the right answer, and a tiny, unconscious signal he made when the horse reached the correct number was all that Hans needed. In fact, not even the psychologist who eventually unmasked Hans was able to control these signals.
However, bees actually can count according to new research. Not very far, and they are no more capable of the four types of calculation than Hans was. Even so, it’s a pretty impressive feat for a creature with a brain the size of a sesame seed. To measure this, honeybees were placed in a tunnel and trained to expect a reward after passing a certain number of landmarks, regardless of how far they had to fly. It turned out that bees could count up to four, and once they had learnt to do that, they were able to count the landmarks even if they were a new type they had never seen before.
And bees aren’t just good at maths (well, considering their size), they are also good at languages.
Dancing Bee People
At around the same time as von Osten and his not-so-clever horse were alive, a future Nobel Prize winner was growing up in the neighbouring country of Austria. Even as a child Karl von Frisch loved animals and his mother must have been extremely tolerant, since she put up with the abundant array of wild creatures he brought home as pets. Over the course of his childhood, he noted 129 different pets in his journal, including 16 birds, 20-odd types of lizard, snakes and frogs, and 27 different fish. Later, as a zoologist, he was especially interested in fish and their colour vision. But almost by chance – largely because his aquatic research subjects displayed an unfortunate tendency to kick the bucket on the way to the conferences where he was supposed to be demonstrating his experiments – he switched to studying bees instead.
Karl von Frisch made two major discoveries: he proved that bees can see colours and that they can tell each other where to find food by performing a sophisticated dance. This was what won him a Nobel Prize in 1973. Von Frisch showed that when a honeybee finds a rich source of nectar, she returns home to the others and tells them where the flowers are. She dances in a kind of figure-of-eight, waggling her rear and vibrating her wings in the parts of the dance when she is moving in a straight line. The speed of the dance communicates the distance to the flowers, while the direction she dances in, in relation to a vertical line, describes where the flowers are relative to the position of the sun.
Today, bees’ dance language is one of the most well-researched and best-mapped examples of animal communication, but history could have turned out quite differently. In Hitler’s Germany, this research was nearly brought to a halt when it had barely begun. In the 1930s, when Karl von Frisch was working at the University of Munich, Hitler sympathisers scoured the university’s employee roster to root out Jewish workers. When von Frisch’s maternal grandmother proved to have been Jewish, he was fired from his post. But he was rescued by a tiny parasite – a parasite that caused a disease in bees that was in the process of wiping out Germany’s bee population. Beekeepers and colleagues managed to persuade the Nazi leadership that von Frisch’s future research was crucial if German beekeeping was to be rescued. The country was at war and in dire need of all and any foodstuffs farming could produce. A collapse of the honeybee population was unthinkable. Thus, von Frisch was able to carry on his research regardless, to the benefit of both bee knowledge and von Frisch’s career.
I’ve Seen That Face Before
For a long time, we believed that only mammals and birds were capable of distinguishing between individuals, the very foundation of the capacity to develop personal relationships. This belief persisted until an enquiring scientist, with the help of some model aeroplane paints, began face-painting wasps. The species concerned was Polistes fuscatus, an American member of the family of paper wasps. Paper wasps build nests from chewed-up wood fibre, which look like a rosette of small larval cells. The nest hangs on a stalk, like an upside-down umbrella. Unlike regular stinging wasps, which also build nests from wood pulp, paper wasps’ nests do not have a protective envelope around the comb of larval cells.
This wasp lives in a strictly hierarchical society, where it’s crucial to know who’s the boss. Maybe that’s why they’re so good with faces. A wasp whose face had been painted in a way that altered her pattern of stripes met with an aggressive reception from her fellow inhabitants when she returned to the nest. They didn’t recognise her and were confused. As a control, the scientists also painted other wasps without altering their personal patterns. These wasps did not experience any reactions on their return to the nest.
Another fascinating point is that after a few hours of jostling, the other inhabitants of the nest got used to the face-painted wasp’s new look. The aggression diminished and everything went back to normal. The other wasps had learned that this was indeed the same old Waspella, despite her makeover. This implies that the wasps actually have the capacity to recognise and distinguish between individual members of their community by their detailed facial cues or ‘features’.
Honeybees take the whole business up a few notches: they can distinguish between human faces in the form of photographic portraits. What’s more, they can remember a face they’ve become familiar with for at least two days. It is doubtful whether the bees relate to what they are actually seeing. They seem to believe the portraits they are presented with are really funny flowers, with the darker areas of eyes and mouth representing recognisable patterns on ‘petals’ that are actually the outline of the portrayed face.
This is new and exciting information, which forces us to rethink how facial recognition actually works: after all, we’re saying that a creature whose brain is smaller than the letter ‘o’ in this book is able to achieve similar things to us humans, with our cauliflower-sized brainboxes. Greater understanding of these processes may be able to help people who suffer from face blindness (prosopagnosia), which is a neurological disorder characterised by the inability to recognise faces.
Perhaps this knowledge can also be used in surveillance – at airports, say. Not by installing a glass cage of buzzing bees to scrutinise us sternly as we go through customs (although that would be pretty cool!), rather by translating the principles that enable bees to recognise facial patterns into a logic that computers can follow. One hope is that this could lead to improved automatic facial recognition – of, say, wanted criminals – via surveillance cameras in crowded places.
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