Army ants dynamically adjust living bridges in response to a cost–benefit trade-off
Abstract
Complex systems, from ant colonies to stock markets, share a common property: sophisticated group-level structure emerges from simple individual-level behaviors. Using simple interaction rules, Eciton army ants construct complex bridges from their own bodies to span forest-floor gaps. These living bridges are uniquely complex in both their dynamic properties and the number of animals involved and so are of considerable interest for understanding emergent structures in complex systems. In field experiments, we show that construction interacts with traffic rate and environmental geometry, causing bridges to lengthen, widen, and migrate. Bridges provide a shortcut for foraging ants, at the cost of sequestering workers. We show that bridge location represents a cost–benefit trade-off, with potential implications for human engineered self-assembling systems.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 23, 2015
- Source ID
- 10.1073/pnas.1512241112
Entities
People
- Albert B Kao
- Chris R Reid
- Iain Couzin
- Matthew J. Lutz
- Scott W. Powell
- Simon Garnier
Organizations
- Army Research Office
- George Washington University
- Harvard University
- Human Frontier Science Program
- Max Planck Institute for Ornithology
- National Science Foundation
- New Jersey Institute of Technology
- Office of Naval Research
- Princeton University
- University of Konstanz