Figure 2. Effect of ambient light intensity on walking speed and pause duration and frequency in the nocturnal ant, Myrmecia pyriformis.

(a) Example trajectories of 9 ants and pauses they made (blue dots) on their foraging route at (i) 0–30 minutes after sunset, (ii) 30–60 minutes after sunset and (iii) 60–90 minutes after sunset. Time taken to travel from the nest to tree is shown as means±SD. (b) Pause duration and (c) walking speed of animals plotted against light levels. Two nests were studied and are indicated as red and black. Regression lines for each dataset are shown.