This video from The New York Times on the physics of fire ants is absolutely captivating. Who knew large numbers of ants could ooze, sludge-like, from a funnel, or spring back, rubber-like, when subjected to compressive forces?
Via the NYT:
These images illustrated the findings of the more technical research, done with rheometers to measure the precise viscosity and elasticity of balls of ants under stress. The researchers found that in different situations the ants behaved differently.
To flow, they moved around, rearranging themselves in the group, acting like a thick fluid. When the aggregation struggled to keep its shape, the ants clung to each other, acting like an elastic solid — rubber for example.
The research could have practical implications, [said Georgia Institute of Technology Researcher David Hu], for self-assembling robots, which build themselves out of smaller bits and for self-healing materials.