Trail image, trajectory overlay, and collective movement pattern. (a) Example trail image from GoPro footage of colony MP1. Individual ants are labeled with identification numbers. (b) All of the trajectories from a single night of footage (January 14) at colony MP1. Each line across the trail represents a different ant, with the different colors distinguishing between different ant tracks. (c) The trail space from (a) was divided into a grid with each square representing approximately 1 cm2. The number of times an ant walks into a square of the grid was calculated and the darker colors represent areas of the trail that ants walked over more. Each heatmap represents a different date (January 11 through January 14) from approximately the middle of the night to control for differences in the timing of filming. Different scales were used for each night, due to variance in the number of ants that walked across the trail.