Eat or be eaten! This could be the motto of the desert locust Schistocerca gregaria that is famous for its impressive and devastating mass migrations. In a recent paper in Current Biology (see the cover on the right), Sepideh Bazazi and its colleagues showed that the collective motion of locust bands is driven by cannibalistic interactions: individuals in marching bands tend to bite others but risk being bitten themselves by their followers. This simple (yet weird) principle triggers an autocatalytic feedback that results in directed mass migration.

Ryan Chisholm get inspired by this scientific result. He designed a funny flash game where you become a locust trying to bite incoming conspecifics and to avoid being bitten by them. Useless therefore necessary!