The activity of the ant Camponotus detritus was studied in the dunes of the central Namib Desert. Activity was divided into two components: transit activity and honeydew collection. Temperature governed both forms, but light controlled the initiation and termination of transit activity, which was bimodal in warm conditions and unimodal in cool conditions. No transit activity occurred at night. Ants were active over a surface temperature range of 10-55°C. Owing to a steep thermal gradient above the sand surface during the day in summer, the temperatures which the ants' bodies experienced at 5 mm above the sand were 10-15°C lower than surface temperatures; well within the ants' physiological limits. In summer, the number of ants collecting honeydew was negatively correlated with air temperature while in winter it was positively correlated. Keywords: Camponotus detritus, desert arthropods, Namib Desert, Namib Desert dune ant.