🇬🇧 | I’m Madalina Bejinariu and I had the opportunity and pleasure to take part in the last phase of the exchange program Europe Convergence in Germany. I’ve talked with Dr. Susanne Foitzik, currently teaching evolutionary biology at Johannes Gutenberg University Mainz, about ants and during this discussion, I discovered a lot of fascinating things about the secret life of ants : their remarkable organisation, without any authoritarian leadership ; a language based on olfactory signals, with their antennas ; their boundless devotion to the laying queen ; their importance in biodiversity and the danger of climate change on their survival.
There are about 15.000 described ant species in the world, but the estimates are that there are about 30.000 ant species. Most of them live in tropical regions, but we can see them on almost any continent (except for Antarctica). They are so tiny that most people do not even notice them. They are present in cities too, but mostly in parks and places where you can see a little bit of grass and soil.
As it’s a topic that is not so discussed about, not in the media or other contexts, shedding more light on this subject became my purpose within the Europe Convergence project. I’ve started looking for scientists and specialists whom I can talk to in order to find out more about these tiny creatures. This is how I found Dr. Susanne Foitzik, an evolutionary biologist, behavioral scientist, and international authority on ants.
Susanne Foitzik is currently teaching evolutionary biology at Johannes Gutenberg University Mainz. After she completed her doctoral studies in the USA, she was a teaching assistant in zoology for four years, and then taught behavioral ecology at the university in Munich.
Susanne Foitzik has written a book on the incredible and fascinating drama that unfolds beneath our feet. Ants are growing stronger colonies, mating, staging wars, growing fungi as crops, or raising aphids as livestock.
Even though they seem so small and helpless, they are indeed very strong (they can carry a weight that is 5.000 heavier than their own body mass). Besides, when you find out that there is no management system, everything becomes even more interesting. Because contrary to what some might believe, the ant queen is not directing or managing in any way the behavior of the colony. It has only one job: to lay eggs and grow the colony bigger and bigger.
When I got the question from my friends and colleagues “Why this subject?”, the answer came naturally. Ants are so interesting especially because they have existed since the dinosaurs; and there are 10 quadrillion ants worldwide. Combine this with the fact that they do not have a manager, and the topic becomes way more interesting. Their species’ longevity is proof that they are doing something successfully.
So, how are ants organizing themselves when there is no central control? When there is no upper management? When the queen is not telling the workers what to do? I have found the answers to these questions and some more curiosities about ants by talking with dr. Susanne Foitzik in Mainz. The discussion was very inspiring, especially because dr. Susanne Foitzik is a positive and passionate human. I feel we could’ve talked for hours about ants and not only, but unfortunately, I was time-limited. However, I’ve found a lot of interesting and fascinating things about ants I will share with you in the following lines.
How Is the Colony Started?
Well, when ants reach a stable number in the colony, they send their fertile and virgin queen to mate with males. After mating, the males die, and the queen rips off her wings (only fertile ants have wings) and digs a hole in the ground. It will live for quite a few years (I’ve found out that there is evidence of a queen ant being alive for 40 years, which is quite impressive).
Ant Colonies – An Insight into How Organizations Work
You can look at ants to understand how organizations work. And how different parts of an organization interact to create the behavior of the whole organization. All ants live in colonies with one queen ant that is just laying eggs, and all the ants you see walking around are sterile female workers. No ant directs the behavior of another ant, so how are the colonies organizing themselves in such a successful way?
“We see that ants have quite a division of labor”, says dr. Susanne Foitzik. “It’s normally an age-dependent division of labor”. At first, young workers are doing brood care. What is fascinating is that an ant is not performing the same task for the rest of its life in the colony. As it gets older, it will change the tasks it will perform. Usually, ants begin by taking care of the brood, then they advance to construction and defending the nest. “And then the oldest ones are the ones which go out and do foraging.” As ants start doing their tasks, they get positive feedback which allows them to get specialized.
What is curious about this task allocation process is that experienced and older individuals are the ones going outside. “So, why do older individuals go outside? Because these are very risky tasks. We have a lot of ants getting eaten by predators or they lose their way to the colony. And the risky tasks would rather be done late in life because then the colony loses less workforce. So basically, the young ones have a lot of life ahead of them, a lot of work they can do. So, they should do the internal work and then the older ones go outside”, explains Susanne. “But the thing is, with the self-organization and the threshold model, it also means that, if need be, all workers can do all tasks”.
For example, there is a species of ants that lives in an acorn. They are so small that the entire colony can fit into an acorn, which is quite impressive. But what can happen is that a deer can kick the acorn for example, so the ants who are out foraging will not find the colony anymore. And to not let the queen and larvae die, other ants will go out and forage for food.
Everyone has probably seen that the number of ants performing a task changes depending on the context and conditions. For example, when extra food becomes available, there are more ants allocated to this task. We have all seen this during picnics. But how do they let each other know that there is more food available, for example?
Ants use a network of antennal contact. They smell with their antennae. When ants are touching antennae, they are smelling each other and can tell what task was the other ant doing. Because ants cover themselves and each other, through grooming, with a layer of grease, which carries a colony-specific odor (ants smell differently depending on the task they do). “They have up to 70 different glands which produce rather complex chemical messages if you wish.” When an ant finds more food available, on her way home to the nest will lay a little trail that will help other ants find the food. These signals will evaporate after a few hours or days, mainly after all the food has been exploited.
How Can Queen Ants Live for so long?
There is evidence of queen ants living for 40 years. “So how? Well, for one thing, there are not a lot of external risks. The queen is never going outside after it did her mating flight and it is in a safe environment. The workers also often keep it quite isolated and foragers do not have direct contact with the queen so that they will not transmit diseases. We know that once diseases are detected in a colony, the first thing they do is to put the queen in quarantine. If there is a starvation period, everybody will starve, but not the queen. So, it gets the best care and the best food. Still, you have to live for so long. We compared gene expressions in young and old queens and found out that there are a lot of typical anti-aging pathways in queens. So, they are actively fighting aging”, explains Susanne.
How Is Climate Change Affecting Ants?
The highest diversity of ants is in tropical regions, which are among the main ones affected by deforestation and climate change. Moreover, the intense use of pesticides and insecticides in agriculture is seriously damaging the soil and ants’ resources.
Protecting the ants is essential as they have a very important function for the ecosystem. Along with the spiders, they are among the most important predators in the arthropod world. “They collect a lot of dead insects, so they help the nutrients recycling. Because they live in the soil, they relocate materials and kind of air the soil”, says Susanne.
Now with the climate change happening, we see a lot of insects moving north in search of the optimal climate. But the problem is that these habitats kind of disappear. So, it is important to adopt healthy habits that help stop climate change. There should be fewer chemical fertilizers, insecticides, and pesticides used in the agricultural sector. Also, “we should try to shift to renewable energy as much as we can and stop cutting down the tropical forests”, explains Susanne. And, of course, we should also work on stopping pollution, as it is seriously affecting the ant colonies. For example, the war in Ukraine has also affected the biodiversity of the country. “When you destroy the soil, you destroy nests and these colonies are dead.”
📝 © Madalina Bejinariu