Cover: A Cataglyphis fortis desert ant tethered on top of a newly designed air-cushioned, spherical treadmill is tested for its navigation performance under natural open sky in its North African desert habitat. Dahmen et al. (pp. 634–644) found that the homing runs of desert ants tested in the field and indoors in the laboratory on the treadmill are comparable to natural homing runs on open ground. The schematic drawing shows the fictive homing trajectory of one ant with the straight approach phase and the looping search phase recorded by the treadmill system. Photo credit: Matthias Wittlinger.