Abstract: Oryzaephilus surinamensis and Cryptolestes ferrugineus are serious secondary pests of various stored commodities and food products. Despite their general morphological similarity (i.e. flattened body shapes typical for invaders of food packaging), the two species differ profoundly in their climbing abilities on smooth surfaces: O. surinamensis is a good climber, but C. ferrugineus is not. In our work we tested whether the difference in climbing ability is reflected in a difference in ability to infest packaged food through ventilation/pressure relief holes.To give a proximate explanation of the differences between the two species, we studied (based on scanning electron microscopy) tarsal morphology of the two species. Description differential tarsal morphology and presence/absence of adhesive setae are presented.