Chemical cues in the form of glandular secretions may play an important role in the location and selection of shelters in lizards. The present study investigated the possible existence and significance of a composite group signal in the group-living cordylid, Cordylus cataphractus. Cordylus cataphractus is very sluggish and probably extremely vulnerable during periods away from the crevice. A group signal would aid dispersing or lost individuals in locating groups of conspecifics in the shortest possible time. Choice experiments to determine shelter selection were conducted in the laboratory as well as in the field, in order to test specific predictions following from the group signal hypothesis. In the laboratory, there was a statistically significant preference for shelters marked with conspecific glandular secretions over unmarked shelters. In the field, individuals strongly avoided crevices occupied by conspecifics. It seems likely that a composite group signal does exist, and that such a signal may be used to locate groups of conspecifics. Whether an individual will actually join a group seems to be determined by the interaction of a number of complex factors.