Movie 1.

Vertical movement of the centre of mass (COM) and the tarsi in Camponotus fellah workers and males. Sample high-speed videos in lateral view of minors, medias and major workers and of males in original speed and slow motion (x0.0625). All ants moved at an intermediate walking speed (minor caste: ∼100 mm s^-1, media caste: ∼75 mm s^-1, major caste: ∼80 mm s^-1, male caste: ∼90 mm s^-1).