Why bees are secretly one of Earth's most intelligent creatures
Bees are winged insects that feed on nectar and pollen, and sometimes make honey. There are around 20,000 bee species, of which 270 live in Britain. More than 90 per cent of bee species are solitary, but the remainder, which includes honeybees and bumblebees, live socially in colonies that incorporate a single queen, female workers and male drones.
The biggest bee – Wallace’s giant bee – grows up to 4cm long, while the workers of some tiny, stingless bees are smaller than a grain of rice. Bees are found on every continent, except Antarctica, and in every habitat that contains insect-pollinated flowering plants.
They pollinate many of the plants that we depend on for food and yet they’re in decline. The number of
bee species has been decreasing for decades and, in Britain, the insects have been lost from a quarter of the places where they used to be found 40 years ago.
How intelligent are bees?
Bees are highly intelligent creatures. They can count, solve puzzles and even use simple tools.
In one experiment, bees were trained to fly past three equally spaced, identical landmarks to reach a sugary reward that was placed 300m away. When the number of landmarks was subsequently reduced, the bees flew much further, and when the number of landmarks was increased, the bees landed at a shorter distance.
This suggests that the bees were counting the landmarks to help them decide where to land.
In another study, scientists created a puzzle box that could be opened by rotating a lid to access a sugar
solution. When a red tab was pushed, the lid rotated clockwise. When a blue tab was pushed, it spun the other way. Not only could bees be trained to solve the puzzle, but they could also learn to solve the problem themselves, by watching other bees complete it.
Regarding tool use, Asian honeybees are known to collect and smear fresh animal faeces around the entrance to their nest, in order to deter predatory giant hornets. It might smell a bit off, but this still counts as tool use.
Scientists had previously shown that bees can learn to use tools in the lab, but the faeces discovery from 2020 was the first observation of tool use by bees in the wild.
The anatomy of a honeybee
The head includes:
1. Two compound eyes 2. Three smaller, single-lensed eyespots, called ocelli 3. Antennae to detect odours, tastes, sounds and temperature 4. Mandibles for chewing, most often the material used to make their nests 5. Proboscis for sucking up nectar, honey and water
The thorax comprises:
6. The midsection of bee 7. Three pairs of legs 8. Two pairs of wings
The abdomen is where you'll find:
9. The crop, or honey stomach, for carrying nectar back to the nest 10. The stinger - a sharp organ used to inject venom
How do bees communicate?
Bees have two primary modes of communication: expressive dance and expressive smell.
Honeybees use the famous 'waggle dance' to direct nestmates to nectar - and pollen-rich flowers. Returning from a successful recce, a worker hurries to one of the hive's vertical honeycombs and begins to trace a figure of eight pattern.
When she gets to the straight part in the middle of the shape, she vibrates her abdomen and beats her wings. This is the eponymous waggle.
The duration of the waggle indicates the distance to the flower, with each second adding an additional 100m to the journey. Communicating direction is more complicated, but can be done by the bee orienting her body in the direction of the food, relative to the Sun.
The intensity of the dance indicates the richness of the food source, while the dancer also releases a cocktail of pheromones that seems to spur the nestmates into action. Colony members watch the dance, sample the odours with their antennae and then head off to find the flowers.
There are other dances, too. The waggle-less ‘round dance’ is used to denote the locations of flowers
that are very close by, while the ‘tremble dance’ is performed by forager honeybees to recruit colony members to collect nectar from the workers.
How do bees navigate?
Bees often travel miles to forage in faraway flower patches, and yet are able to find their way home with unerring accuracy. All this, with a brain that’s smaller than a sesame seed. So how do they do it?
Firstly, they use the Sun as a compass. Bee eyes are sensitive to polarised light, which can penetrate thick cloud. This means that even on a cloudy day, bees can still ‘see’ the Sun and use it as a guide. The position of the Sun is combined with an indication of time from the animal’s internal clock, enabling the bee to keep track of both direction and distance.
The bee also monitors how much the Sun moves during the journey, so when she returns to the colony she can tell her nestmates the position of the food relative to the Sun’s current position, rather than its position when she found the food.
Finally, honeybees are known to be able to sense magnetic fields, through some sort of magnetic structure in their abdomens. So researchers think that bees may also use Earth’s magnetic field to help them navigate.
What does a bumblebee nest look like?
Bumblebees are the plump, furry bees that look as though they shouldn’t be able to fly. Britain has 24 species, six of which are parasitic and 18 that are social.
Social species, such as the garden bumblebee, form colonies and build nests in sheltered spots, away from direct sunlight. Abandoned rodent burrows and compost heaps are good places, as are bird boxes, holes in trees and the spaces underneath sheds.
Unlike honeybee nests, which are elaborate structures with hexagonal cells, bumblebee nests are scruffy structures with disorganised cells. Often insulated with leaves or bits of animal fur, they’re designed to hold small numbers of bees (around 40 to 400) for a single nesting season.
Honeybee nests, in contrast, can house up to 40,000 individuals and can last for years.
Parasitic bumblebees, such as the aptly named red-tailed cuckoo bee, don’t make nests of their own. Instead, their queens invade the nests of other bumblebees, where they kill the resident queen and lay their own eggs, which are then raised by the resident workers.
When did bees evolve?
Wasps are reputedly sadistic and generally reviled, while bees are seen as benevolent and widely adored – yet bees evolved from wasps.
Bees belong to the order Hymenoptera, which also includes sawflies, ants and wasps. The oldest known Hymenopteran fossils are from the Triassic Period, around 224 million years ago. Wasps made their debut during the Jurassic Period, between 201 and 145 million years ago, followed by bees in the Cretaceous Period, between 145 and 66 million years ago.
Trigona prisca was one of the first. A stingless honeybee found immortalised in New Jersey amber, it was on the wing around 85 million years ago. The key specimen is a female with a small abdomen, which indicates that she was a worker, and that some bee species had already organised themselves into complex social structures.
The first animal-pollinated flowers had already evolved by this time and were being pollinated by beetles, but the evolution of bees drove the evolution of flowering plants, which drove the evolution of bees, and so on.
It’s one of the finest examples of coevolution. Flowers evolved nectar and funnel-shaped heads, while bees evolved longer tongues to sup the nectar, and specialised hairs to transport the pollen.
Can humans live without bees?
Probably, yes. But the disappearance of bees would pose a serious threat to global food security and nutrition.
One out of every three mouthfuls of food we eat is dependent on insect pollinators, such as bees. Whether it’s staples, such as potatoes and onions; fruits, from apples to watermelons; or seasonings, like basil and coriander, bees help to fertilise plants when they transfer pollen between them.
Coffee and cocoa plants, for instance, both depend on bees for pollination, as do around 80 per cent of European wildflowers.
Bees are also a source of food for many birds, mammals and insects. If we lost the bees, we would lose the roles they play in their ecosystems, with knock-on effects for many other animals and plants.
It’s bad news, then, that bees are in global decline. Habitat loss, intensive farming methods, pollution, pesticide use, disease and climate change are all to blame. And a recent study found that the global loss of pollinators is already causing around 500,000 early deaths a year in humans, by reducing the supply of healthy foods.
What should I plant for a bee-friendly garden?
Most bee species aren’t too fussy about where they get their pollen and nectar from, so plants such as lavenders, hollyhocks and marigolds will attract a good range of bees.
Other species, however, are more specialist and depend on a smaller number of plants. These bees are often rare and if the plants that sustain them disappear, then the local population may be at risk.
Grow yellow loosestrife for the yellow-loosestrife bee, a medium-sized bee that frequents the plant for its pollen and scented oils. Females use the oils to waterproof their nests, which can often be found on the edges of ponds and rivers.
Lamb’s ears are an easy-to-grow, evergreen perennial favoured by the wool-carder bee. Female wool-carder bees use fibres from the soft, furry leaves to line their nests, while males defend territories that contain these plants.
Another easy option is to let your lawn grow long and embrace the weeds.
Dandelions and related plants, such as hawkbit and hawkweed, are a favourite of the pantaloon bee, which gets its name from long hairs on the females’ hind legs that get coated in pollen and look like clown trousers. Similarly, buttercups are a magnet for large scissor bees and sleepy carpenter bees.
Five common bee myths... busted
1. Bees are too heavy to fly - This myth can be traced back to the 1934 book Le Vol des Insectes by Antoine Magnan, who erroneously believed that bee wings are too small to generate the requisite lift for flight. He was wrong, obviously.
2. All bees sting - Male bees can't sting. The stinger is a modified egg-laying device and is found only in females. There are also around 550 species of stingless bee, which have stingers so small that they can't be used defensively.
3. Bees die after stinging you - Of the bees that can sting, only honeybees die after stinging. Barbs in their stingers get snagged in the victim's skin and as the bee tries to free itself, its abdomen becomes fatally ruptured.
4. All bees make honey - Most bees don't make honey. In fact, there are only eight species of true honeybee that make large amounts of the sweet stuff. There are hundreds of other bee species that make it too, but in much smaller quantities.
5. All bees are hard-working - As busy as a bee, right? Queens lay up to 1,500 eggs per day. Worker bees forage, feed the young and spruce up the hive. Male bees, however, don't have much to pack into their day. A drone's one and only role is to mate with a virgin queen.
