How Ants Help the Planet (and Do Lots of Other Amazing Things)

An author of "Empire of Ants" describes how the tiny insects develop vaccines, wage wars, and grow gardens.


Olaf Fritsche / "Empire of Ants"

What they might lack in size, they make up for in numbers.

Researchers estimate that there are 10 quadrillion ants on Earth. Sure, they like to crash picnics, but they also have an amazing array of capabilities, according to evolutionary biologist and myrmecologist (ant expert) Susanne Foitzik and biophysicist and science journalist Olaf Fritsche.

The pair teamed up to write the just-released "Empire of Ants," where they share that some ants develop vaccines to avoid diseases, cultivate fungi gardens, wage wars, and even raise aphids as working livestock.

Filled with stories of their discoveries, travels, and the problems scientists face when studying such tiny creatures, the book is also filled with colorful photographs of these cute, but fierce insects.

Foitzik talked to Treehugger by email about her work and what captivates her about these amazing creatures.

Treehugger: Where did your fascination with ants begin? When did you decide you wanted to be a myrmecologist?

While I did observe ants in our garden, when I was a kid, my real fascination with these social creatures began during my Master thesis. I was interested in the evolution of animal behavior, having worked on social interactions and sexual selection in birds and mice before. I started to study ants during my Masters in the field and in the lab for several months. I became fascinated with their social complex behaviors, but also about how aggressive their do defend their nests. And the small Temnothorax ants, that I mainly study, are really cute. An entire colony fits into an acorn.

two ants watercolor

 Susanne Foitzik / "Empire of Ants"

What have you learned about ants their cities, their social structure, their work ethic that most impresses you?

One part of my research focuses on socially parasitic ants and I investigate the coevolution between them and their hosts, ants of a different species. Dulotic, or “slavemaking ants“ as they have been called, conduct recurrent raids on free-living host colonies to steal their worker brood. Once these stolen workers emerge, they work for the social parasites, conducting all necessary task in their colony from brood care to foraging.

Our work could show that dulotic ants use chemical weapons to manipulate defenders in attacking each other instead of turning against their attackers. We could show that some host become resistant to this manipulation and that in some populations, such as one from New York, enslaved ant workers rebel against their oppressors and kill their offspring. These fights and selfish acts, occur in acorn nuts and sticks in the leaf litter on the forest floor right at our feet and we often do not even know it. 

You write that an ant is helpless without its colony, but when ants work as a team they are practically unstoppable. How have you witnessed this in an impressive way?

Indeed, during nest relocations ant guide other ants often during tandem runs. One ant is leading the way, but often the follower gets lost, turning helplessly in search for her guide. You need patience when you observe them, it all looks highly inefficient, and yet at the end of the day, the entire colony managed to relocate to the new nest site.

up close with an ant
Up close and personal with an ant.

Olaf Fritsche / "Empire of Ants"

While humans are doing no favors to the planet, ants are beneficial. What are some of the ways ants help the environment?

Especially soil-living ants air the soil and recycle nutrients. Many ant species are generalists that feed on dead insects; they are the garbage collectors or undertakers of the ecosystems. Finally, as ants are ubiquitous and populous, they engage in close interactions with many other organisms, from aphids (which they tend), to plants which they defend and inhabit) to fungus which leaf cutting ants grow in their underground chambers. 

There are thousands of different species of ants. Of those you’ve studied, do you have favorites and why? What are the “rock stars” of the ant world and those that are fascinating but don’t get quite the fanfare?

I do like the social parasites, which I have mentioned above. Dulosis in ants arose several times independently and occurs in many different branches of the ant tree of life. Parasitic ants outsource the work to ants of other species, and actually by doing so lost the ability to care for themselves, are unable to even feed and have to be fed. They lost many chemical receptors and as ants mainly communicate chemically, they are blind to many signals of their world.

Another very enigmatic group are army ants, which I have studied in Malaysia. These restless vagabonds hunt at night through tropical forests and their huge swarms overwhelm all kind of prey that is in their way. Their coordination is fascinating, but astonishingly enough even in these huge nests uninvited guests, other arthropods, such as beetles, spiders, or silverfish have made their home and live from the resources of these fierce army ants as parasites. 

ants watercolor

 Susanne Foitzik / "Empire of Ants"

How far have you traveled and to what lengths have you gone to study an ant species?

Ant hunting as we call it, is by far the most favorite part of my job. I have studied ants in Europe, Asia, South and North America, from the tropical rainforests over the deserts in Arizona to the boreal forests of Northern Russia. Studying ants and collecting their colonies can vary depending on species and habitat.

We have observed army ants and leaf cutter ants in the rainforests of Malaysia and Peru at night, we dug deep into the soil of Arizona to collect social paraites, and we opened acorns and small sticks in the temperate forests of Russia, Germany, Italy, England, the US and Canada to find the tiny Temnothorax ants, that nest in them. We cut ourselves with knives, were stung by aggressive wasps and bitten by rattlesnakes and yet being out in Nature and encountering all kind of wildlife from porcupines to black bears still fascinates me. 

What are some of the challenges of studying insects that are so tiny?

Yes ants can be tiny, so that many observations are difficult in the field, especially if they do not nest in open areas but in forests or even up in the canopies. Yet, under the microscope, these tiny animals are easy to observe and when marked you notice how complex their social networks are, the division of labor in their tiny self-organized communities.

Yet when we want to study genes underlying their complex behaviors, we have to dissect their brains out, no easy task then the head is a large as the pin of needle. But with a steady hand even this is possible.