Fish in schools can take it easyUsing a new computer model, researchers at the Ecole Centrale de Marseille and CNRS have shown that a fish expends less energy when it swims in a school, because neighbouring fish produce a 'suction' effect. This work will be published on 11 May 2018 in Physical Review Letters . Schools of fish provide a fascinating example of collective behaviour in which the group moves in a coordinated manner without the need for a leader.