SOME are smart, some are stupid; others charge in with reckless abandon while more cautious characters take time to weigh up their options; they can also be hard working or a bit lazy.
The tiny, but amazing mind of a bumblebee produces a welter of traits that are all too recognisable to a very different animal: humans.
While insects may appear to us as little pre-programmed automata, a study published today highlights dramatic d
ifferences in what might be described as the bumblebee version of intelligence.
This adds to the weight of evidence showing highly complex behaviour from an animal with a brain the size of a grass seed.
They can count, recognise different people from their faces and have navigation skills to rival the finest cab driver, thanks in part to their in-built magnetic compass.
And that's not to mention senses humans can barely imagine, such as the ability to see ultra-violet and polarised light and their extraordinary talent for detecting smells, so good that they are starting to be used to find hidden explosives.
Dr Nigel Raine, lead author of the scientific paper published by the Royal Society, said the researchers had tested how quickly 12 different bumblebee colonies would realise only yellow flowers contained nectar, in a lab with both yellow and blue ones.
The smartest colonies realised this after trying about 15 different flowers and their collection performance shot up by 80 per cent, while the slower learners visited 70 flowers before spotting the pattern.
"We found a five-fold difference between the fastest and slowest learning bees," said Dr Raine, of Queen Mary's school of biological and chemical sciences in London.
"A lot of people have this very simplistic view of insects, that they are little pre-programmed automata, but they are very good at learning these things.
"They are learning by experience. You make mistakes and, hopefully, you learn from them. That's the same way we learn about things. There are similarities.
"But whether you can equate that to intelligence, that's quite a difficult one. It is one measure of cognitive performance so you could say intelligence in a very loose sense."
Some bumblebee species are being driven to extinction – mainly due to the loss of suitable nesting sites and the right type of flowers – and Dr Raine said it might be possible to breed smarter ones which would be better able to cope with the changing environment.
But too much time learning – or over-thinking the situation – might not be a good idea in all cases.
"We don't know necessarily if that's a good thing. There's some evidence that bees are quite limited in what they can do with their energy budget," he said.
"If they expend a lot of energy on learning, that might allow them less resources to fight off infection."
There are 25 native bumblebee species in Britain and Ireland – out of 300 worldwide – but three have become extinct here and five others are in a precarious position.
Professor Lars Chittka said those species which relied on specific flowers were struggling while "generalists" seemed to be faring reasonably well.
He detailed some startling similarities between bumblebees and humans, but also stressed their "alien" nature.
"Some individuals are sloppy and fast and make rapid choices but get things wrong. Others are a bit slow, but highly accurate," Prof Chittka said.
"If errors get penalised, the bees will all become slower so they have more time to make accurate choices."
Within the hive, some will respond to the need to tidy up more quickly than others.
"It's a bit like, say, in a human household some individuals get more disturbed by a huge pile of things in the sink so they start washing them up," he said.
"Some individuals have a lower threshold for responding to something that needs to be done."
Like humans, bumblebees naturally live in social groups of about 50 to a few hundred and have a division of labour with nectar foraging, pollen foraging, hive climate control and cleaning all considered different jobs.
"The queen is kind of the boss, in the sense she actively suppresses egg laying by other workers – she has a monopoly on that unless she gets very old and tattered when some of the workers might try and take over the show," Professor Chittka said.
"The day-to-day labours are not decided by any central hierarchy, but by the needs of the colony.
"If there's a shortage of nectar then that information is available to those foragers that engage in nectar foraging and they will start foraging for nectar. The organisation is entirely decentralised."
While honeybees live in "rigorously organised" colonies of tens of thousands of individuals, the smaller bumblebee colony – often an abandoned mouse house – tends to be "a bit more messy, a bit more anarchic".
"A honeybee hive is more Tesco-like, versus your little corner store (the bumblebee hive]," Prof Chittka said.
Bumblebees do produce honey but cannot match the factory-style production of their smaller cousins.
"It is very delicious, but you wouldn't fill a single glass with the honey from one bumblebee colony. It would be very expensive," he added.
Prof Chittka stressed bees were very different from other insects.
"If you think about it, they cannot just be reflex machines. That's already obvious from the fact they have a hive," he said.
"Other insects such as flies and butterflies are aimlessly drifting across the countryside, but bees fan out from the hive over a territory the size of central London and have to find their way back to the nest. If they don't find their home again, they are dead.
"If you took a school class of eight-year-olds, placed them in central Tokyo where they couldn't read any of the signs and asked them to fan out, find something and come back... how many would be able to do it?
"Bees with their pinhead brains solves these problems all the time. That demolishes the idea of a bumblebee being a reflex automaton."
However, it is not the surprising similarities between human beings and bees that attracted him to study the insects that he describes as "aliens on planet Earth".
"I like bumblebees a lot. Some people like them because they look like little teddy bears, they are furry and colourful," he said.
"I like them because they are so alien. They have sensory abilities humans just do not have. It is rather fascinating how they evolved sensory aspects which are inaccessible to us."
And Prof Chittka cautioned against anyone getting carried away with ideas of bumblebee philosophers.
"They have a form of intelligence, but I suppose if you faced bees with a human IQ test they might not do all that well."
Tests reveal high flyers earn their stripes IN the experiment, researchers tested the foraging ability of 12 bumblebee colonies each containing about 30 to 40 workers.
The Bombus terrestris bees were initially trained to forage from 20 artificial flowers, each coloured both blue and yellow and containing a sucrose solution reward.
Bumblebees, identified by a number and colour, which completed five foraging trips were then taken to a "flight arena" containing ten blue flowers and ten yellow ones, with only the latter containing any sucrose.
They were then monitored, and every time they landed on a flower or approached it, this was regarded as making a selection.
Choosing a yellow was regarded as a correct choice, choosing a blue one was deemed an error. The researchers stopped recording data after a bee had made 99 flower choices after visiting a yellow one for the first time.
This enabled the scientists to produce a learning curve, comparing the number of flower choices against the number of errors.
The Royal Society paper said: "On average, bees from the fastest learning colony took only 15 flower visits to achieve an 80 per cent improvement in task performance, while bees from the slowest-learning colony took 71 visits to reach the same performance criterion. These two colonies differed in learning speed by a factor of 4.7."
The "smarter" bumblebees were also found to do better in the wild, harvesting 66 per cent more nectar than the slowest learning colonies from real flowers under field conditions.
This comparison was achieved by excluding several bees at the bottom of the class.
"Eight out of 180 bees showed no appreciable improvement in performance during the task and the software generated 'learning curves' that were essentially horizontal lines," the paper said.
The full article contains 1435 words and appears in The Scotsman newspaper.
