1 Department of Collective Behaviour, Max Planck Institute of Animal Behavior, Konstanz, Germany.
2 Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany.
3 Department of Biology, University of Konstanz, Konstanz, Germany.
4 School of Engineering and Information Technology, University of New South Wales, Canberra, NSW, Australia.
5 The National Engineering Research Center of Software Engineering, Peking University, Beijing, China.
6 The State Key Laboratory of Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering, Peking University, Beijing, China.