Ants were investigated at the housing lots of the Ryukyu Islands using manual collecting. In this study, 24 ant species belonging to 12 genera in 3 subfamilies were collected. This corresponds to 16.4% of the 146 ant species confirmed on the Ryukyu Islands. Eighteen (75.0%) of the 24 ant species collected were alien ants. Ant species collected from all of sampling sites surveyed included Nylanderia amia, Pheidole megacephala and Pheidole parva. In this survey, the alien ant species Plagiolepis alluaudi was collected on the Nansei Islands (Naha city on Okinawa-jima) for the first time. Sixteen species were collected on Iriomote-jima (Haimi, Taketomi-cho), but only 9 species were collected on Kume-jima (Kanegusuku, Kumejima-cho) and Hateruma-jima (Hateruma, Taketomi-cho). The similarity of species composition calculated by Nomura-Simpson’s Coefficients (NSC) was greatest (0.90) between Miyako-jima and Hateruma-jima. NSCs between all of the 8 Islands were for more than 0.5.