English: Dynamics of substrate rolling in Nest B. Colour intensity represents the density of ants on the artificial substrate. The substrate shape is not explicitly indicated (see Figure 1), but is highlighted by the distribution of ants. The substrate tip is on the left. Change of colour intensity does not represent the exact number of ants, but serves to give an impression of general dynamics of the construction process. Figure 3 is included in the video as an indication of the colour scale. The initial exploratory phase is followed by groups forming at the tip and the bottom right of the substrate and successive rolling of the substrate tip. Original images were taken every 5 seconds and are displayed at 2 frames per second. Colour maps created with ImageJ.