1. Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, USA
2. School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
3. Department of Biology, University of Konstanz, Konstanz, Germany
4. Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
5. Faculty of Information Technology, Monash University, Melbourne, Victoria, Australia