1 School of Zoology, Tel Aviv University, 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, 6997801, Israel. Electronic address: ayali@tauex.tau.ac.il.
2 Department of Biology, University of Konstanz, Konstanz, 78457, Germany; Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, 78464, Germany.