Many of ant species can discriminate nestmates from non-nestmates, and aggressively reject the latter. For their nestmate recognition cues, cuticular hydrocarbons (CHCs) have been studied. Some ant species that form supercolony are characterized by the absence of inter-nest aggression, therefore the individuals can freely move among nests within a supercolony. We have reported in a supercolony-forming native species, Formica yessensis , that their aggressiveness depends on the disparity of chemical composition of CHC profiles, and so dose the number of the antenal chemosensilla sensitive to CHCs. Also in the Argentine ant, Linepithema humile , their inter-colony aggressiveness depends on the disparity of chemical composition of CHC profiles. To verify whether L. humile mainly use the CHCs to discriminate colonymates from the others like F. yessensis , we performed farther experiments. We compared the behavioral responses of L. humile and F. yessensis to the experimentally given living ants (nestmates or the others) or their purified CHCs. It was then found that F. yessensis , the results on the behavioral responses to purified CHCs are consistent with those to living ants, but that not in L. humile . This suggested that Argentine ant CHCs not so crucial as their colonymate-recognition cues. Otherwise, they might have other strategies different from F. yessensis to exclude non-colonymates.