Ants determine direction by smell

Thanks to the ability to sense many smells at once, a desert ant in Tusinia uses odor information to create an image of the surrounding environment.

Desert Ants Cataglyphis fortis. Photo: sciencecentric.com.

Pigeons, mice and humans can sense many smells at the same time, but so far the scientific world has not yet discovered which animals are capable of using odors to determine the direction.

Dr. Markus Knaden, Dr. Kathrin Steck and Professor Bill Hansson of the Max-Planck Institute of Chemical Ecology, Germany track desert ants Cataglyphis fortis in Tusinia to find out their behavior. Every day they leave away from the nest to 100 m to find food. When finding food, ants return to the nest. What surprised the three scientists was that they determined the direction very accurately when returning. On the desert is flat and there is hardly anything to mark the location, determining the return is extremely difficult work for all animals.

Scientists have long known that ants use complex visual information to determine their direction. But the three German researchers discovered a more interesting behavior. They placed four different types of odors in positions A, B, C and D around the very hard-to-see entrance of an ant nest.

After a few days the expert team brought some ants to a very far place, but they still determined the exact entrance to the nest.

In the following days, the team reversed the position of the odor. Immediately the ants were confused and could not determine the direction. This shows that they determine the direction by remembering the location of the smells.

Another interesting finding is that ants only have one beard that cannot find the nest if two or more smells exist together in the surrounding environment. Thus we can deduce that they need two antennae to determine the exact direction. Each beard can sense the smell in a different direction at the same time. Thanks to that ability, ants can visualize their surroundings thanks to the smell.

"It seems that the harsh conditions in the desert have created the ability to locate by smell in ants," Dr. Knaden said.