According to a new study, ants, which walk backwards when carrying heavy loads of food, use the Sun’s position and visual memories of surroundings to guide them home. The study shows that ant’s navigation skills are more sophisticated than previously thought.
Scientists have shown that ants walking backwards will occasionally look behind them to check their surroundings, and use this information to set a course relative to the Sun’s position. This allows the insects to maintain their course regardless of which way they are facing, researchers said.
“In this way, the insects can maintain their course towards the nest regardless of which way they are facing,” the team of researchers from University of Edinburgh, Scotland, found.
The surprisingly flexible and robust navigational behavior displayed by ants could inspire the development of novel computer algorithms, step-by-step sets of operations, to guide robots.
“Ants have a relatively tiny brain, less than the size of a pinhead. Understanding their behavior gives us new insights into brain function, and has inspired us to build robot systems that mimic their functions,” said Professor Barbara Webb of the University of Edinburgh’s School of Informatics.
The study published in the journal Current Biology.
Scientists studied a colony of desert ants to see how the insects navigate while transporting different-sized pieces of food.
Though, they usually walk forward when they carry small pieces of food, but walk backwards to drag larger items to their nest.
The team sunk barriers into the ground to create a one-way route to the nest. They then gave ants either a small or large pieces of cookie, and observed how they made their way home.
Previous research has shown that ants walking forward find their way by comparing what they see in front of them with visual memories of the route. The team found that ants traveling backwards instead use the Sun’s position in the sky to guide them.
Researchers observed that ants set off in the wrong direction when a mirror was used to alter their perception of the Sun’s location. To ensure they stay on course, backward-walking ants also routinely drop what they are carrying and turn around. They do this to compare what they see with their visual memories of the route and correct their direction of travel if they have wandered.
The findings suggest ants can understand spatial relations in the external world, not just relative to themselves.