Ants use a predictive mechanism to compensate for passive displacements by wind

Insect navigation is a fruitful system for analysing the ingenious and economical mechanisms that can underlie complex behaviour [1]. Past work has highlighted unsuspected navigational abilities in ants and bees, such as accurate path integration, long distance route following or homing from novel locations [2]. Here we report that ants can deal with one of the greatest challenges for any navigator: uncontrolled passive displacements. Foraging ants were blown by a jet of air over 3 meters into a dark pit. When subsequently released at windless unfamiliar locations, ants headed in the compass direction opposite to the one they had been blown away, thus functionally increasing their chance of returning to familiar areas. Ants do not appear to collect directional information during the actual passive displacement, but beforehand, while clutching the ground to resist the wind. During that time window, ants compute and store the compass direction of the wind. This is achieved by integrating the egocentric perception of the wind direction relative to their current body-axis with celestial compass information from their eyes.