Learn from ants how to optimise search for food

Ever wondered how ants find a food source and bring the food to their nest in a matter of minutes?

Ants in group are smarter than individual ants and are capable of complex problem-solving strategies that could be widely applied as optimisation techniques, a study noted.

They have the knack to track the shortest possible trail of a scent-emanating substance called pheromones that the ants leave behind, and bring home the food at the earliest possible time.

"Ants have a nest so they need something like a strategy to bring home the food they find," said Lixiang Li from Beijing University of Posts and Communications.

"The ants collectively form a highly efficient complex network," Jurgen Kurths form Potsdam Institute for Climate Impact Research explained.

The researchers put almost everything that is known about the foraging of ants into equations and algorithms and fed this into their computers.

They assumed that there were three stages of the complex feed-search movements of an ant colony: Initially, scout ants indeed circle around in a seemingly chaotic way.

When exhausted, they go back to the nest to eat and rest.

However, when one of them finds some food in the vicinity of the colony, it takes a tiny piece of it to the nest, leaving a trail of a scent-emanating substance called pheromones.

Other ants will follow that trail to find the food and bring some of it home.

Their orchestration is still weak because there is so little pheromone on the trail.

Due to their large number, the ants go lots of different ways to the food source and back to the nest, leaving again trails of scent.

This eventually leads to an optimisation of the path: Since pheromones are evaporative, the scent is the stronger the shorter the trail is - so more ants follow the shortest trail, again leaving scent marks.

"While the single ant is certainly not smart, the collective acts in a way that I am tempted to call intelligent," Kurths noted.

The study will appear in the journal Proceedings of the National Academy of Sciences.