Two sesquiterpenic compounds, E,E,-alpha-farnesene and E-beta-farnesene, which were previously found as major constituents of the male mouse preputial glands, were tested for their attractiveness to female mice. Sexually naive and sexually experienced females were given the opportunity to choose between natural stimuli and synthetic analogs of preputial chemosignals. Naive females preferred investigating the odors of intact males' urine and synthetic farnesenes when spiked in high concentration in bladder urine or water over control stimulus (water or bladder urine alone). Investigatory preference was not observed when synthetic farnesenes were presented to naive females in low concentration, i.e., only twice the natural content in the dominant male urine. However, sexually experienced females were clearly able to recognize and prefer samples with synthetic farnesenes, even in low concentration. We suggest that those sesquiterpenic compounds may play a wide-ranging role in the female recognition of sexually mature and socially dominant males.