Ants are marvels of the animal world: They’re incredibly strong, extremely resourceful, and their ability to work cooperatively is brilliant (for example, look at the army ants’ nest-of-bodies called bivouacs). Ants are also excellent navigators. It’s long been known that ants use pheromones to follow each other around, but new research shows that ants can also use magnetic and vibrational landmarks to guide themselves around.
What’s crazy is that, rather than blindly following a scent laid down by another ant wanderer, landmarks have to be processed and remembered. So ants can learn? That’s amazing, and kind of scary.
The paper, written by Cornelia Buehlmann with oversight from Bill Hansson and Markus Knaden of the Max Planck Institute in Germany, is published in PLoS Biology. Buehlmann trained desert ants by passing them through tunnels with distinct areas that were had magnetic fields or were vibrating, after which she directed the ants towards the nest. (To make things extra trippy, the team painted the ants to identify them.) With the training aids removed, tests showed that the ants learned the landmarks, and it helped them in their navigation.
To get the nitty-gritty on the learning, GPS-defying ants, I had chat with Knaden to talk musical ant repellents and pigeons taking over the world.
How exactly did you create vibrational and magnetic markers for the ants?
We trained ants in a long aluminum channel to visit a feeder filled with food crumbs and return to a small, almost invisible hole in the channel floor that was connected with the nest entrance. Outside of the channel at the nest position we either glued solenoids on the channel wall (i.e. Invisible to the homing ant but changing the magnetic field at the nest position within the channel) or dug a vibrating rod into the ground (again invisible, but creating vibrations that had the highest amplitude at the nest position).
What spurred the idea for your research in the first place?
For 15 years I’ve done fieldwork in Tunisia with these ants. So far we have trained the ants with all kinds of visual and olfactory landmarks. It was already reported that some other ant species can sense magnetism and vibrations (but in a completely different context), and we were just curious to see whether they can learn such artificial landmarks. I am actually pretty sure that no natural vibrational or magnetic landmarks exist. However, it is great to find that the ants are flexible enough to learn them.
Would playing amplified music make ants get lost, either by the speaker magnets or sound vibration? What if it was really loud?
As far as we know, ants cannot hear. However, really loud music probably could be sensed via the vibrations. Speaker magnets of course could be learned as landmarks like the ones we use in our study. Regarding the vibration, we trained and tested the ants with a continuous and uniform vibration. It would be nice to train them to a specific song and see how well they can distinguish it from other songs. However, I am not 100% sure that the Max Planck Society (that I am working for) would finance such research.
Hypothetically, if sonic ant deterrents worked, what music would you play to chase ants away?
Should be something that does not repel me! So maybe Muse, All, or Boxhamsters.
Who would win in a navigational challenge, ants or pigeons?
Pigeons are still my favorites when it comes to navigation. Maybe that’s the reason why it is still quite uncommon to breed ants and perform mass releases 300km away from home.
Considering that ants can learn, are so single-minded within their colonies, and have such incredible biomass Earth-wide, do you think ants will one day take over the planet?
Definitely. Still better than if pigeons would do so.
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Image via Max-Planck.