SUMMARY

We investigate the swarming of fire ants. Our studies are motivated by applications in the field of swarm robotics in which the building block is a simple programmable element from which complex patterns or behaviors emerge. Intelligence is decentralized as is the case with social insects such as fire ants. While swarming together, fire ants link their legs and mandibles together to form various structures such as floating rafts, towers, bridges, and bivouacs. In this combined experimental and theoretical study, we investigate their means of construction with the vision of providing guidance and design of programmable swarm robotics. Using scanning electron microscopy and computed tomography scans, we quantify the internal structure and connectivity of the ant mass which provides it with rigidity, strength, and water-repellency. Using time-lapse photography, we record the construction and deconstruction rates of ant rafts and towers. We rationalize these rates using mathematical models based on the observed trajectories, behaviors, and quantity of ants in these structures.