We studied similarities and differences in the qualities of individual odors across colonies and species of African eusocial mole rats using habituation techniques. Giant mole rats (Cryptomys mechowi) treated anogenital odors of 2 conspecifics from 1 colony as similar to each other and different from the odor of a conspecific from another colony, providing evidence for kinship odors. Subjects also discriminated between the subtle differences in the individual odors of familiar colony members. In another set of tests, mole rats from 3 species (C. mechowi, C. anselli, and C. kafuensis) treated anogenital odors of genetically closer heterospecifics as more similar to odors of conspecifics than to odors of less closely related heterospecifics. Thus, odor similarities paralleled genetic similarities as determined by the analysis of allozymic and karyotypic distances. The results demonstrate that similarities in individual odors covary with genetic similarities within colonies and across species. These similarities could provide a basis for different types of social recognition based on self-referent matching.