All Aboard! Ants Go to Space for Study to Improve Robotics
A crew of ants kept the astronauts on the International Space Station company as part of the cutely-named Ants in Space CSI-06 investigation, a study intended to improve algorithms for robotics. By learning the mechanisms by which the ants collectively search for resources in different environments, we may be able to develop more efficient strategies for robotic search and exploration.
Principal Investigator Deborah Gordon is an ecologist who has studied ants in a myriad of environments, including tropical forests, the desert, the hills around Silicon Valley, and her own kitchen. Now she can add the microgravity on the ISS to that list, as she was able to observe their communal behavioral changes in this extreme environment.
The search algorithms of ants could help us create more efficient search robots, particularly ones without any central control. Ant colonies have queens, but queens spend their time reproducing and do not generally direct ants in their searches for resources. Instead, ants work together to cover as much ground as thoroughly as possible. They determine how many other ants are around them in order to decide whether breadth or depth is the priority in their search; if there are many other ants, then they search one area very thoroughly, but if there are only a few others, then they cover as much ground as possible. They are able to judge the density of their search party by communicating with their antennae and sensing chemical secretions in order to discern the rate of interaction with other ants. As a result, Gordon calls ants the ideal study subject for collective behavior.
Ants are very adaptable creatures, so Gordon hypothesized that the space station environment would lead to modifications of their search behaviors: "In microgravity, the relation between how crowded they are, density, and interaction rate, might be messed up," she says.
She described the initial image she received from the space station: "When I first saw this picture I thought, 'Oh no, they've mounted the habitat vertically.' But then I realized that of course it doesn't matter. The idea here is that the ants are working so hard to hang on to the wall or the floor or whatever you call it, that they are less likely to interact and so the relationship of how crowded they are and how often they meet would change."
Gregory Vogt, assistant professor with the Center for Educational Outreach at Baylor College of Medicine in Houston, confirmed this finding: "The ants did execute search behaviors and occasionally, an ant lost her footing and tumbled about."
These search algorithms are also similar to the function of data networks. An ant receiving input from the rest of the colony in its search for food is analogous to a signal determining that there is sufficient bandwidth to send out a piece of data. As a result, this study may lead to new data algorithms that could improve data networks.