<p>Anna Dornhaus is peering into a cardboard nest box only an inch on a side, at a “family” of 100 or so European rock ants. Known as Temnos, the ants, painted in primary colours, are going about their ant chores hauling, foraging and nursing the glistening maggoty brood.<br />Next to a colour-coded Temnos, a rice grain would look like an old-growth log. When the lid on an ant colony is raised, a whiff of dead cockroach, ant chow, wafts by. A quiescent larger queen is a study in brown. Nearby are bumblebee hives under glass in which each bee sports a number from 1 to 100 on tiny price-tag-like label attached to its back. <br />To understand what is really going on in a colony of ants or bees, Dornhaus, an assistant professor of ecology and evolutionary biology at the University of Arizona, tracks the little creatures individually, hence the paint and the numbers. Individual ants, she said, have “their own brains and legs, as well as complex and flexible behaviours. Each ant’s behaviour and the rules under which it operates generate a pattern for the colony, so it’s crucial to discover its individual cognitive skill.” <br /><br />How many of them work?<br /><br />Dornhaus is breaking new ground in her studies of whether the efficiency of ant society, based on a division of labour among ant specialists, is important to their success. To do that, she said, “I briefly anesthetised 1,200 ants, one by one, and painted them using a single wire-size brush, with model airplane paint, Rally Green, Racing Red, Daytona Yellow.” <br />After recording their behaviour with two video cameras aiming down on an insect-size stage, she analysed 300 hours of videotape of the ants in action. She discovered behaviour more worthy of Aesop’s grasshopper than the proverbial industrious ants. <br />Dornhaus found that fast ants took one to five minutes to perform a task: collecting a piece of food, fetching a sand-grain stone to build a wall, transporting a brood item, while slow ants took more than an hour, and sometimes two. And she discovered that about 50 per cent of the other ants do not do any work at all. In fact, small colonies may sometimes rely on a single hyperactive overachiever.<br />Under the guidance of Lars Chittka, an expert on the ecology of insect sensory and cognitive abilities, who was studying bumblebees, Dornhaus worked on a thesis on animal behaviour. <br /><br />Bees and their waggle dance<br /><br />Chittka, who said that the bumblebee group, although social, was regarded as primitive in social habits, wondered why a single bumblebee, after returning to the nest, beat its wings excitedly and ran around crazily in circles. Soon the other bees would get excited and leave the nest. He asked Dornhaus to find out what was going on. “I knew that when I looked at this crazy bee it knew something the others didn’t,” Dornhaus said. <br />She designed an experiment, which revealed that the bee was making and broadcasting a pheromone in the hive that alerted other bees: “Hey, there’s food out there.” As Dornhaus said, “Bumblebees don’t have to meet in person to communicate; they leave a note behind on a blackboard for other bees that food can be found.” <br />Dornhaus realised that bumblebees communicate in ways that resemble a waggle dance. The idea that bumblebees were so primitive that they were incapable of complex communication was “destroyed by Anna’s work, and was published in Nature,” Chittka said. <br />The honeybee waggle dance, performed in tight figure eights, in which a bee returns to the hive to inform its nest mates where the food is, is one of the most remarkable discoveries in animal communication. It is the closest approach to symbolic language of any creature apart from humans. <br />But Dornhaus questioned what the honeybees actually got out of the waggle dance. No scientists had questioned its basic function.<br />The dancers depend upon a vertical dancing platform for direction and orientation, but Dornhaus flipped some beehives on their sides at her study site among agricultural fields in Germany. Deprived of the appropriate stage, the honeybee scouts still danced, but it was random. <br />Dornhaus then moved her study to the thyme, lavender and wild rose shrublands of Spain, repeating her experiment and refining it. “I weighed each returning bee, but my results were the same,” she said. <br /><br />Work in India<br /><br />Because honeybees evolved in the tropics, Dornhaus’ next field site was in the Nilgiri Hills in the Western Ghats. She bought some Indian bee hives in Bangalore. But the recalcitrant Indian bees “just packed up and left,” she said. Local farmers, braving considerable stings, tried to replace them by stealing a nest from a tree. Again, the Indian bees deserted. Dornhaus resorted to European honeybees, and they stayed put. <br />Tropical forests are known for biological diversity, but from a honeybee’s perspective, they are a green desert, because flowering trees are widely spaced. <br />“A honey bee is less than an inch long,” Dornhaus explained. “If it flies 20 kilometres that equals 787,400 body lengths. If we say a human is two metres tall, then in human terms, that would be like travelling 394 kilometres and back, possibly several times a day.”<br />Again, the flipped hives interrupted the informative dances. The bees could not find the flowering trees and went hungry. Dornhaus concluded that the value of the dance depended on the environment.<br />Dornhaus’ own agile work on social insects has attracted the attention of computer scientists and engineers because “they need such algorithms to design artificially distributed problem-solving systems.”<br /></p>
<p>Anna Dornhaus is peering into a cardboard nest box only an inch on a side, at a “family” of 100 or so European rock ants. Known as Temnos, the ants, painted in primary colours, are going about their ant chores hauling, foraging and nursing the glistening maggoty brood.<br />Next to a colour-coded Temnos, a rice grain would look like an old-growth log. When the lid on an ant colony is raised, a whiff of dead cockroach, ant chow, wafts by. A quiescent larger queen is a study in brown. Nearby are bumblebee hives under glass in which each bee sports a number from 1 to 100 on tiny price-tag-like label attached to its back. <br />To understand what is really going on in a colony of ants or bees, Dornhaus, an assistant professor of ecology and evolutionary biology at the University of Arizona, tracks the little creatures individually, hence the paint and the numbers. Individual ants, she said, have “their own brains and legs, as well as complex and flexible behaviours. Each ant’s behaviour and the rules under which it operates generate a pattern for the colony, so it’s crucial to discover its individual cognitive skill.” <br /><br />How many of them work?<br /><br />Dornhaus is breaking new ground in her studies of whether the efficiency of ant society, based on a division of labour among ant specialists, is important to their success. To do that, she said, “I briefly anesthetised 1,200 ants, one by one, and painted them using a single wire-size brush, with model airplane paint, Rally Green, Racing Red, Daytona Yellow.” <br />After recording their behaviour with two video cameras aiming down on an insect-size stage, she analysed 300 hours of videotape of the ants in action. She discovered behaviour more worthy of Aesop’s grasshopper than the proverbial industrious ants. <br />Dornhaus found that fast ants took one to five minutes to perform a task: collecting a piece of food, fetching a sand-grain stone to build a wall, transporting a brood item, while slow ants took more than an hour, and sometimes two. And she discovered that about 50 per cent of the other ants do not do any work at all. In fact, small colonies may sometimes rely on a single hyperactive overachiever.<br />Under the guidance of Lars Chittka, an expert on the ecology of insect sensory and cognitive abilities, who was studying bumblebees, Dornhaus worked on a thesis on animal behaviour. <br /><br />Bees and their waggle dance<br /><br />Chittka, who said that the bumblebee group, although social, was regarded as primitive in social habits, wondered why a single bumblebee, after returning to the nest, beat its wings excitedly and ran around crazily in circles. Soon the other bees would get excited and leave the nest. He asked Dornhaus to find out what was going on. “I knew that when I looked at this crazy bee it knew something the others didn’t,” Dornhaus said. <br />She designed an experiment, which revealed that the bee was making and broadcasting a pheromone in the hive that alerted other bees: “Hey, there’s food out there.” As Dornhaus said, “Bumblebees don’t have to meet in person to communicate; they leave a note behind on a blackboard for other bees that food can be found.” <br />Dornhaus realised that bumblebees communicate in ways that resemble a waggle dance. The idea that bumblebees were so primitive that they were incapable of complex communication was “destroyed by Anna’s work, and was published in Nature,” Chittka said. <br />The honeybee waggle dance, performed in tight figure eights, in which a bee returns to the hive to inform its nest mates where the food is, is one of the most remarkable discoveries in animal communication. It is the closest approach to symbolic language of any creature apart from humans. <br />But Dornhaus questioned what the honeybees actually got out of the waggle dance. No scientists had questioned its basic function.<br />The dancers depend upon a vertical dancing platform for direction and orientation, but Dornhaus flipped some beehives on their sides at her study site among agricultural fields in Germany. Deprived of the appropriate stage, the honeybee scouts still danced, but it was random. <br />Dornhaus then moved her study to the thyme, lavender and wild rose shrublands of Spain, repeating her experiment and refining it. “I weighed each returning bee, but my results were the same,” she said. <br /><br />Work in India<br /><br />Because honeybees evolved in the tropics, Dornhaus’ next field site was in the Nilgiri Hills in the Western Ghats. She bought some Indian bee hives in Bangalore. But the recalcitrant Indian bees “just packed up and left,” she said. Local farmers, braving considerable stings, tried to replace them by stealing a nest from a tree. Again, the Indian bees deserted. Dornhaus resorted to European honeybees, and they stayed put. <br />Tropical forests are known for biological diversity, but from a honeybee’s perspective, they are a green desert, because flowering trees are widely spaced. <br />“A honey bee is less than an inch long,” Dornhaus explained. “If it flies 20 kilometres that equals 787,400 body lengths. If we say a human is two metres tall, then in human terms, that would be like travelling 394 kilometres and back, possibly several times a day.”<br />Again, the flipped hives interrupted the informative dances. The bees could not find the flowering trees and went hungry. Dornhaus concluded that the value of the dance depended on the environment.<br />Dornhaus’ own agile work on social insects has attracted the attention of computer scientists and engineers because “they need such algorithms to design artificially distributed problem-solving systems.”<br /></p>