A Motor Component to the Memories of Habitual Foraging Routes in Wood Ants?

SummaryAnts are so low to the ground that slight undulations in the terrain over which they navigate will cause large and unpredictable changes to their view of the scene around them. We describe here evidence of a form of motor learning that helps ants follow their usual route when guiding landmarks vanish from sight. Wood ants were trained to approach a vertical bar presented at varying positions on a LCD screen. In different experiments, the bar was either stationary, moved smoothly, or jumped between two stationary positions. Ants trained in these three ways followed straight, curved, or two-leg routes, respectively. Once ants were accustomed to approaching the bar from different starting points, the bar was made to disappear during their approach. Ants often continued their straight or curved or two-leg paths, despite the missing landmark, showing that they can perform complex routes with no more than intermittent visual feedback.