The Great Ant Migration: A Tiny World in Motion
Leading by hand, porting luggage, foiling thieves and navigating the unknown—how ants relocate.
March 4, 2025 | Shivani Lamba, Asian College of Journalism
The tiniest smidgen of sugar falls on the floor, and soon a trail of organisms appears. Who are these black and red-colored creatures? Ants. They not only forage but are often shifting houses—carrying their food and family along. For us humans, relocating our house is often an exhausting and overwhelming process. But why do ants relocate, and how do they manage it?
At the eighth edition of Science at the Sabha, Annagiri Sumana, a Professor at the Indian Institute of Science Education and Research (IISER)Kolkata, opened a window to the world of ants and answered these questions drawing from her lab’s research. This annual public event organized by The Institute of Mathematical Sciences, Chennai had four talks from various disciplines.
Breaking myths about ants
Most people believe there are only two types of ants: black and red. Red ants are known for their painful bites, while black ants are considered harmless. However, this is a misconception. The world is home to over 12,000 species of ants—higher than the total number of mammals or birds on Earth. These ants come in a variety of colors, from shades of brown to even green.
They are found almost everywhere in the world, except in polar regions where the extreme cold prevents their survival. Despite their small size, ants have a massive influence on ecosystems, playing crucial roles in soil aeration, pollination, seed dispersal, plant protection, and nutrient cycling.
Ants as guards and farmers
Some ants even have specialized relationships with plants. Certain species feed on the sugary secretions of plants and, in return, protect them from herbivorous insects. This mutualistic relationship benefits both ants and plants, forming an essential part of many ecosystems.
Another fascinating fact about ants is their ability to farm. Some species cultivate fungus gardens, much like human farmers grow crops. These ants cut leaves into tiny pieces, chew them, and place them in designated chambers where the fungus grows. The worker ants then feed on the spores produced by the fungus.
Do all ants make trails?
A common sight in homes and gardens is a line of ants marching toward a food source. But do all ants form these trails? Surprisingly, no. While many species use pheromone trails to guide colony members toward food, several hundred species do not. These ants forage alone, carrying food back to the nest individually.
Studying ant behaviour
Each ant colony has a strict hierarchy. The queen is the sole reproductive individual, while worker ants perform various tasks such as foraging, defense, and brood care. There are further divisions within the workers—some have strong mandibles and act as soldiers, while others tend to the young.
To study ants, researchers like Sumana mark individuals with paint, with unique colour codes for each member of the colony. This allows scientists to track each individual and study their role within the colony. Observing these individually identified ants provides insights into division of labour, communication, and decision-making within their intricate societies.
Why do ants relocate?
Relocation can be exhausting. Packing, planning, and moving from one place to another takes effort. But what about ants? They also relocate—when their home is damaged, there is competition from neighbours, or when resources are running low.
Where do ants live? Just as birds live in nests and humans build homes from mud and brick, some ant species create underground nests with intricate tunnel systems akin to a “compact studio apartment”. Sumana spoke about her lab’s research on one such ant species known as Diacamma indicum. They may form colonies of a few tens to over two hundred ants, consisting of the queen, workers and soldiers. Like humans, ants spend a significant amount of time inside their homes.
Transporting one's offspring: Do all organisms do it?
When humans relocate, they always take their children along. But can all organisms carry their offspring from one location to another? The answer is no. Many species leave their young behind, unable to transport them. But ants? They take everything—including their fragile brood—during relocation.
Ant colonies consist of various life stages—eggs, larvae, and pupae, all of which require special care. The colony is the most invested in the pupa stage, which will soon transform into an adult. The larvae are fragile, and the eggs are the most delicate. Yet, ants manage to transport them carefully, ensuring the survival of the next generation.
How do ants relocate?
Relocating a colony is not an easy task, especially when transporting fragile young. Sumana's research has found that ants of the species Diacamma indicum use tandem running to lead their colony members to a new nest location. Tandem leaders are very efficient in navigating unknown terrain and can find some of the shortest routes between the old and the new nest site. During a tandem run, much like holding hands, a follower ant maintains physical contact with a tandem leader as the latter guides it to a new location. Once the site is chosen, workers transport eggs, larvae and pupae.
The followers carefully carry the brood with them, manoeuvring their large load through tiny spaces with help from others. They also watch out for brood thieves—ants from neighbouring colonies out to steal their young ones. Whether escaping a flood, avoiding competitors or seeking better shelter and resources, ants execute relocation in an organized and efficient manner, within six hours on average.
Lessons from ants
Ants, despite their size, exhibit remarkable problem-solving abilities and adaptability. Their relocation strategies and cooperative behaviour offer valuable lessons in teamwork and efficiency. The next time you see a line of ants carrying their belongings, remember—they may be executing a big move, a miniature version of what humans experience.
Edited by Bharti Dharapuram
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Sumana's talk is available to watch online on the Matscience YouTube channel.
Shivani Lamba can be contacted at shivanilamba108 [at] gmail [dot] com.
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