It's easy to get lost in the salt pans of Tunisia.

There are these featureless planes in the desert, where the ground is sometimes the blinding

white color of salt.

So it's a very strange feeling and some people already feel uncomfortable there, because

you basically don't see anything.

Marcus Knaden is at the Max Planck Institute for Chemical Ecology, in Yenna, Germany.

And he does field work in the salt pans with his colleague Marie Leaffreira.

So actually the car that we drove was often the landmark, so we could know how to return

back to it, because it's very easy to get lost.

While it's easy to get lost for them, that's not really the case for their study subjects.

A type of desert ant that can walk for more than half a mile over these flat planes and

still find its way home.

And to be fair, the ants have a few tricks to be able to do that.

What we know from them is they use some compost to get an idea in which direction they walk,

and they count their steps to get an idea the distances they cover in the individual

directions.

And by that they always compute their relative position to the nest.

But the scientists noticed the ants had another trick, too.

The farther their burrows were into that flat featureless plane, away from plants and rocks

and other landmarks, the more the ants tended to build these big mounds at the entrances

of their nests.

They're like volcano-looking humps in the salt pan, sometimes more than 10 inches tall.

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