The Namib Desert along the south-western coast of Africa supports a sand dune fauna without counterpart elsewhere in the world. The trophic base of the arthropod fauna is wind-blown detritus. Aperiodic advective fog collection from vegetation or detritus is a possible source of water for diverse Namib animals. For the specialised fauna living in vegetation-less dunes, fog collection from detritus, disturbed sand projections, directly from humid air, or from water precipitated on the body, seem to be the only possible water uptake methods. Water uptake from saturated or subsaturated air, demonstrated for a few arthropod species, is not a physiological capability of Namib tenebrionids already investigated.