To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S1. Time lapse showing the position of a bridge over time with the apparatus set to an angle θ of 20°. Each frame advances 5 min into the experiment. Army ants dynamically adjust living bridges in response to a cost–benefit trade-off Chris R. Reid, Matthew J. Lutz, Scott Powell, Albert B. Kao, Iain D. Couzin, and Simon Garnier PNAS. 2015. DOI: 10.1073/pnas.1512241112 Download Original Video Browse All Videos »