Hundreds of ants get together to make a bridge to help fellows ants to get to the other side

Researchers from Princeton University and the New Jersey Institute of Technology report that the "living" bridges built by army ants of the species Eciton hamatum (pictured) are more sophisticated than scientists knew. The ants automatically assemble with a level of collective intelligence that could provide new insights into animal behavior and help in the development of intuitive robots that can cooperate as a group. The ants form living bridges without any oversight from a "lead" ant and with a clear cost-benefit ratio. The ants will create a path up to the point when too many workers are being diverted from collecting food and prey. Bridges are the length of 10 to 20 ants -- only a few centimeters -- but swarms form several bridges a day, which save collective energy and maximize foraging time. Video courtesy of Matthew Lutz, Princeton University, and Chris Reid, University of Sydney