Fire Ants May Hold the Secret to Future Search-and-Rescue Robots

Fire ants may finally have something besides their nasty bite to contribute to this world, according to researchers at Georgia Tech who believe their discoveries regarding the creature’s tunneling behaviors may one day be applied to tunneling robotics.

Among the ants’ fundamental “principles” when it comes to digging, the scientists found, is that of building tunnel environments that assist in moving around by limiting slips and falls as well as reducing need for complex neural processing.

Another is the reliance on antennae for locomotion as well as for sensing for the environment when the ants find themselves confined in spaces.

“The environment allows the ants to make missteps and not suffer for them," Daniel Goldman, an associate professor in the School of Physics at the Georgia Institute of Technology, and one of the paper’s co-authors said in a press release. "These ants can teach us some remarkably effective tricks for maneuvering in subterranean environments.”

In order to come to these resultsthe scientists placed fire ants into tubes of soil and allowed them dig tunnels for 20 hours while they, the researchers, simulated a range of environmental conditions by varying the size of the soil particles as well as the moisture content.

In the end, while these variables affected the volume of tunnels produced and the depth to which the ants dug, the diameters of the tunnels remained constant at a rate comparable to the length of their bodies.

“The size of the tunnels appears to be a design principle used by the ants, something that they were controlling for,” Goldman said of the observation.

Nick Grave, the graduate research assistant who carried out the experiments, hypothesizes that the size of the tunnels has to do with making the best use of the ants’ antennae, limbs and body in order to rapidly ascend as well as descend by interacting with the walls and limiting the number of missteps.

What’s more, by dropping mazes containing the ants and their tunnels, one student discovered that the ants used their antennae to grab onto the tube walls as they fell.

“A lot of us who have studied social insects for a long time have never seen antennae used in that way,” Michael Goodisman, a professor in the Georgia tech School of Biology and another one of the paper’s co-authors, said. “This is an adaptive behavior that we never would have expected.”

By further analyzing ants falling in the glass tubes, they determined the diameter of their tunnels plays a key role in their ability to brace for a fall.

Such discoveries, of which there were 168 in all, could have major implications in the world of robotics, the researchers believe.

“The problems that the ants face are the same kinds of problems that a digging robot working in a confined space would potentially face – the need for rapid movement, stability and safety – all with limited sensing and brain power,” said Goodisman. “If we want to build machines that dig, we can build in controls like these ants have.”

Among the kinds of robots the scientists envision applying their research toward are those performing undergruond search-and-rescue missions.

The study was published in the Proceedings of the National Academy of Sciences and was sponsored by the National Science Foudnation's Physics of Living Systems program.