Fire ants interlock their legs together to______.

Fire ants living in Brazilian forests are perfectly adapted to an environment prone to flooding.(21)To save themselves from drowning, they lock their legs together, creating floating rafts, up to 20 centimeters wide.
    According to mechanical engineer David Hu, ants know how to interlock tightly.
    "If you can imagine you have a hundred ants, which means 600 legs.(22)Ninety-nine percent of those legs will be connected to a neighbor so they’re very, very good at maintaining that network," he said.
    To discover the secret of their engineering,(22)Hu and his colleagues at the Georgia Institute of Technology froze ant rafts and then analyzed them with a CT scanner.
    They found out that larger ants serve as hubs to which smaller ants hold, forming pockets of air that keep them afloat.
    Scientists say small robots or advanced materials that can configure themselves could be programmed in a similar way, working toward a shared goal.