November 3, 2015
Most people consider ants a nuisance. They can’t wait to get rid of the pests. However, myrmecologists, or scientists who study ants as a branch of entomology, or the study of insects, find ants and their behaviour fascinating.
Why? For one, ants may be tiny but they can carry more than double their weight and withstand pressures up to 5,000 times greater than their own body weight. It appears ants are also smart. Considered to be a wise king, even Solomon exhorted lazy people in his kingdom almost 2,500 years back to “Go to the ant, you sluggard! Consider her ways and be wise.” The quote can be traced to the Book Of Proverbs in the Old Testament of the Christian Bible.
Ants know what hierarchy is—the queen ant, soldier ants and the working class. Ants, myrmecologists will tell you, can also teach you how to collaborate—they form symbiotic associations with a range of species, including other ant species, other insects, plants and fungi.
Research over the years has consistently reinforced the belief that ants collectively are pretty smart. The study of this trend is known as swarm intelligence. The concept, not restricted to ants alone, propounds that a single ant or bee is not smart but their colonies are. It is this study of swarms of ants and bees that has provided insights to help humans manage complex systems—from truck routing to military robots.
The secret lies in the way ants communicate with each other using pheromones, sound and touch. Pheromones are defined as chemicals that insects and animals produce to alter the behaviour of another insect or animal of the same species. You can liken these to chemical signals. For instance, when a food source is exhausted, no new trails are marked by returning ants and the scent slowly fades away, prompting other ants to explore new routes.
Ants also use pheromones to alert their kind to attacks. If you ever step on ants which have lined up to collect pieces of grain that have fallen on the ground, you will notice them scattering in different directions immediately—that’s the pheromone effect.
The field of ant robotics has been inspired by swarm robots that can communicate through markings, similar to ants that lay and follow pheromone trails. American electrical engineer James McLurkin was the first to conceptualize the idea of “robot ants” in 1991, while working at the Computer Science and Artificial Intelligence laboratory at the US’ Massachusetts Institute of Technology (MIT).
Then there are the Ant Colony Optimization (ACO) algorithms that have been applied to many problems, ranging from the routing of vehicles to producing near-optimal solutions for the travelling salesman problem. ACO algorithms can be run continuously and adapt to changes in real time. This is of interest in network routing and urban transportation systems. It was Italy-born scientist Marco Dorigo who first proposed the ACO in his PhD thesis in 1992. In fact, the first ACO algorithm was also called the Ant System.
Researchers have furthered their study of ants over the years. Using mathematical modelling and field data, researchers at the mathematics department at Sweden’s Uppsala University have now discovered the basic rules that allow ants to build efficient and low-cost transport networks without discarding robustness. The study was published in the journal Interface on 21 October.
It was a two-year-long field study that provided the researchers a large data set consisting of several trail networks built by the Australian meat ant to connect different nests spread over a wide territory.
The researchers developed a model to understand how these networks have formed. Using data and numerical simulations, they were able to identify a general mechanism of local cost minimization as the basic rule that leads to a balance between competing design goals.
The study showed that when building a new nest, the ants connect it to the closest nest available and possibly to a tree, where the ants feed, if it is not too far away.
The researchers have tried to apply “the same simple rules to predict what would happen to man-made systems, electric grids for example, if they were built by these ants”, according to Arianna Bottinelli, a PhD student at Uppsala University.
Cutting Edge is a monthly column that explores the melding of science and technology.
Disclaimer:The views expressed above are the author’s own