Scientists discover how desert ants navigate

An international research team led by Dr. Pauline Fleischmann from the University of Oldenburg (Germany) has just discovered that the desert ant species Cataglyphis nodus has the ability to orient itself based on the Earth's magnetic field.

This report was published in the journal Current Biology.

Notably, they use the polarity of the magnetic field (North-South axis) instead of the "tilt", which is common in many other insects.

This discovery not only sheds light on the unique orientation abilities of desert ants, but also hints at their unique magnetic sensing mechanism, which is different from many other animals.

The Amazing Orientation Skills of Desert Ants

Desert ants can sense the north-south direction of the magnetic field to determine the direction to enter their nest. (Photo: eurasiareview).

Desert ants live in harsh environments such as the salt flats of the Sahara or the pine forests of Greece. With no clear landmarks, they can still travel hundreds of meters in search of food and return to their nests in a straight line.

Dr. Fleischmann and his colleagues conducted a series of experiments with ants from Greece. They were placed in a system of Helmholtz coils that created artificial magnetic fields of different directions and strengths. The goal was to test the ants' response to changing the magnetic field strengths.

When the researchers changed the tilt of the magnetic field—the angle between the magnetic field lines and the Earth's surface—the ants' orientation behavior did not change. However, when the north-south axis of the magnetic field was reversed, the ants oriented completely the wrong way, assuming the nest entrance was in a different location.

Based on these results, the team concluded that desert ants do not rely on the tilt of magnetic fields like birds or butterflies. Instead, they use the polarity of magnetic fields to orient themselves over short distances, a mechanism that acts like a mini ' compass . '

Different magnetic field sensing mechanism

There are currently two main hypotheses about how animals sense magnetic fields:

• Radical pair mechanism: Light-dependent quantum effect, commonly seen in songbirds or butterflies.
• Magnetic beads: Tiny magnetic beads in neurons that act like compass needles, common in species such as sea turtles, bats, and pigeons.

The team suspects that the desert ants' magnetic sensing ability involves magnetic particles such as magnetite (an iron mineral), rather than a radical pair mechanism.

Significance of the discovery

The discovery not only expands our understanding of how animals navigate, but also lays the groundwork for studying the evolution of magnetic sense in the natural world. "This type of compass based on magnetic polarity is particularly useful for navigating short distances, which is crucial in the harsh habitats of desert ants," said Dr Fleischmann .

This study also opens up new directions in understanding the orientation mechanisms of other species such as bees and wasps.

The discovery that desert ants use a completely different mechanism to sense magnetic fields than species like butterflies or cockroaches shows the incredible diversity in the animal world.

Similar studies in the future could help humans gain a deeper understanding of how animals adapt to harsh habitats, and provide ideas for advanced positioning technology.