Long coevolution of prey and predator species of mammals creates specific mechanisms of their interaction, e. g. prey's innate behavior aversive to the predator odor. However, little is known about genetic responses in the prey organism. We assessed genome instability of the bone marrow cells in mice affected by the cat's odor influence, and proposed pathway of such action. Materials and methods: CBA mouse ma les were exposed to volatiles from adult cat urine for 2 or 24 hours. To estimate the genetic effect, ana-telophase method of chromosome aberration analysis and comet assay were used. The level of corticosterone was also measured after the exposure for 30 or 60 minutes. Results: The exposure to cat's urine volatiles for 2 hours induced damage of DNA in bone marrow cells of the mouse males as was shown by the DNA comet analysis. The exposure for 24 hours elevated the frequency of chromosome aberrations in mitotically dividing cells at ana-telophase stage. No significant changes were found in the level of corticosterone in the peripheral blood. Conclusion: We have shown that volatile chemosignals from predator's urine induce genomic instability in bone marrow cells of a prey. The hormonal pathway of such influence is still unknown. Intraorganismic paths leading to genome damage are discussed as well as far consequences of discovered effects.