Ants in the lead: How ants cooperate in steering food to their nest

A physics-based model can explain how ants cooperate in steering food to their nest. To lug a large object, a number of ants surround it — the back ones lift, those on the leading edge pull. How do they stay on track, instead of simply pulling all around in a sort of tug-of-war? Scientists used video analysis to track the individual movements of ants in a group that was carrying a large food item toward their nest.