We studied the prey preference and feeding behaviour of adult males of Ocypus olens (Müller) (Coleoptera: Staphylinidae), an active predator of many insects, under laboratory conditions. Tests were carried out individually on eight types of carabid beetles: three species with chemical defences and aposematic colours, Brachinus sclopeta (Fabricius, 1792), Anchomenus dorsalis (Pontoppidan, 1763) and Chlaenius velutinus (Duftschmid, 1812), and five species without these characteristics, Pseudophonus rufipes (De Geer, 1774), Steropus melas italicus (Dejean, 1828), Amara anthobia Villa & Villa, 1833, Poecilus cupreus (Linné, 1758) and Calathus fuscipes (Goeze, 1777). Ocypus olens preferred to attack prey without chemical defences and aposematic colour patterns, possibly stimulated by the prey's type of movement.