Ant Pedometers: How Ants Navigate

Ants Marching
 are amazing creatures. Sure, they can be a pest when the get into your home. The last thing that you want to see is a trail of ants across your kitchen floor. However, in the wild, ants do some amazing things.

Many species of ants work together in structured communities. They divide the labor just like other social insects such as bees and wasps. There are ants that tend to the young, tend to the queen and those who defend the nest and do the work.

Ants can carry many times their own weight and some species can team up to create a terrifying defense of the nest. Some species go on hunting runs that will wipe out almost every living thing in their path. Some other ants can run super fast or fly out of the path of danger.

The most important thing for any ant colony is finding food. How do ants find a food source and then know to come back there again and again? It’s not like they can draw maps or pull out their cell phones and use GPS. They do leave chemical trails, but there’s more to it than that.

Now, thanks to scientists willing to attach stilts to ant’s legs, we have a slightly better idea of how they navigate. 

Stars and Steps

Ant PonderingAccording to an article in New Scientist, prior studies indicated that some ants use stars and the position of the sun for navigation purposes. That doesn’t mean they were using tiny telescopes and sextants. All of this navigation is part of their nervous system and something they do automatically, without conscious thought and computation.

However, scientists at the University of Ulm, Germany, felt that this was not enough of an explanation. Ants that live in desert environments travel on mostly flat terrain. Thus, they need some way to calculate distance.

The University of Ulm researchers conducted a study by setting up an aluminum channel about 10 meters long and put a food source at one end. They let the ants do what ants do – find their way from the nest to the food source and back.

Now it was time to alter the ants a bit.

Stilts and Shorts

The scientists took the tiny desert ants and immobilized them safely. They then set about altering their legs. To do this required steady hands and keen eyes.

The scientists needed lengthen and shorten the legs of some of the ants. Some ants had tiny bristles attached to their legs. This extended the length of their legs by 1 millimeter. Essentially, these ants were given stilts.

Other ants had their legs shortened by as much as 1 millimeter without hurting the ants. In nature, when an ant gets stuck in the ground or within the grasp of a potential enemy, they often break off parts of their legs. The missing parts grow back and do not affect the ant’s life-span.

Next, the researchers set the ants back to their nest and let them do what came naturally. The results were interesting.

A Little Too Far, a Little Too Short

The ants with the stilts ended up walking well past the place the food. The same food that they had found without trouble just the day before, was now hard for them to find. Some of the stilt-ants went 50% further than they needed to and then got confused and wondered where the heck the food had moved, before turning around and heading back home.

The ants with shortened legs had the opposite reaction. Many of them went 50% less than they had just the day before.

The effect only lasted for a short time. Even those with altered legs eventually found their way back to the food source and adjusted accordingly.

Ants Count Steps

Ant Carrying LeafWhat were the scientists to conclude with this? Well, the conclusion is that ants have built-in pedometers.

They “count” the number of steps from their nest to the food and back again. Yes, they may also use the sun and stars like an internal compass to help with the navigation, but calculating the distance is one of the key factors to finding food.

Of course, we should not immediately hire ants to start doing our accounting. They are not consciously counting steps like we would.

Just like with the internal compass, the ants are doing this as part of their nervous system. It is an internal device that allows them to find a food source and find their way home, leaving those chemical trails for their fellow ants. It’s a key part of their survival. The scientists theorize that the internal counter resets each time they go back to their nest.

This study goes a long way toward helping us understand how ants work and how they live. It’s also rather amusing to imagine a scientist painstakingly attaching stilts to the legs of ant, too.

If you have a problem with ants, those with stilts or otherwise, be sure to call the ant control experts at Ehrlich.

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