Scientists have created miniature robots that successfully replicate the behavior of a colony of moving ants.

Researchers from the New Jersey Institute of Technology and the Research Centre on Animal Cognition sought to learn how ants orient themselves when part of a moving group, traveling complex paths from nests to food supplies. To do so, they created a group of sugar-cube- sized robots called "Alices" that left light trails, detectable with light sensors akin to an ant's antennae. Ants normally orient themselves by leaving chemical pheromone trails. The researchers focused their study on Argentine ants.

They theorized that the success of the ants' foraging was due to instinctive behavior, rather than individual calculations. They tested the theory by comparing real ants with the robotic ones. About 500 ants were deprived of food for two days, then let loose in a maze carved into a plastic board. The researchers observed how the ants acted as they scrambled toward a cotton ball soaked in a sugar solution at the opposite end of the maze.

The robots were programmed to move like real ants and came with two Swatch watch motors and four small wheels. They could get up to about eight feet per minute, which is about four times the speed of a real ant. Once in a cardboard maze, they followed lights that mimicked pheromone intensity. After repeating the two experiments several times, the researchers found that the routes and rates of success were very similar, though the robots did tend to find shorter routes.

"This research suggests that efficient navigation and foraging can be achieved with minimal cognitive abilities in ants," says lead author Simon Garnier. "It also shows that the geometry of transport networks plays a critical role in the flow of information and material in ant as well as in human societies."

The study was published on Thursday March 28 in the journal PLOS Computational Biology.