Ants, just like motorists, hate congestion and use alternative routes to avoid it, scientists said on Wednesday.
The industrious insects push and shove each other out of the way when it gets too crowded, forcing some to find another route from a food source back to the nest.
"Ants are able to find a solution when they are faced with congestion on trails," said Vincent Fourcassle, a biologist at the Centre for Cognitive Animal Research in Toulouse, France.
In a study published in the science journal Nature, Fourcassle and a team of researchers analyzed videotapes of thousands of ants in an experiment on collective movement.
Using a mathematical model, they explained how the individual behavior of the ants affected their collective movement and group behaviour.
Foraging ants prefer to carry food along a favourite trail that is marked with scent clues. In the experiment, the insects had to cross a diamond-shaped bridge between the location of the food and their nest.
Fourcassle said that if the two branches of the bridge were quite wide, traffic on the preferred route was much heavier. But when the branches were narrowed and the ants encountered a bottleneck getting to the favourite route, congestion on both branches was more equal because ants chose the alternative route.
Pushing seemed to be the favourite way to maintain a steady flow of food back to the nest.
