June 12 - Fire ants are among nature's greatest engineers, working together with their own bodies to form rafts that are almost unsinkable. Researchers have long wondered how they do it but now, with a freezer and CT scanner, scientists at Georgia Institute of Technology have unravelled part of the mystery. Rob Muir has more.
Fire ants are prodigious engineers. They have evolved to cope with frequent flooding in their Brazilian rainforest habitat by turning themselves into interlocking units that together, form an almost unsinkable raft. Scientists at Georgia Tech, say they now know how the ants do it, although they had to freeze entire rafts in the lab, and CT scan the individual insects to find out. Assisant Professor David Hu says the raft is a marvel of engineering. SOUNDBITE (English) DAVID HU, GEORGIA TECH ASSISTANT PROFESSOR, SAYING: "The ants connect with themselves very, very, very well, more than we had thought. If you can imagine you have a hundred ants, which means 600 legs. Ninety-nine percent of those legs will be connected to a neighbour so they're very, very good at maintaining that network." And they do it systematically with larger ants forming central hubs for their smaller neighbours to hold onto. As a group, they also maintain spaces between their bodies, giving the raft greater bouyancy. Hu says the ants have lessons to teach human engineers. SOUNDBITE (English) DAVID HU, GEORGIA TECH ASSISTANT PROFESSOR, SAYING: "Well, there's a lot of interest in active materials, small robots or materials that can configure themselves to build larger, more capable objects and now we know it's quite possible for scientists to do so.if we just follow what the ants are doing." . But one thing CT scans can't reveal is how the ants know where to go and what to do. Hu says that is a mystery still to be solved.