Recent observations of social behavior and reproduction in wolves, coyotes, hunting dogs, mongooses, and lions suggest possible involvement of pheromones in the regulation of reproductive activity. Observed phenomena resemble the known pheromonal effects in mice such as suppression or synchronization of estrus, induction of maternal behavior, and interruption of pregnancy. Further studies are necessary to verify the supposed biological effects of carnivore pheromones and to determine their chemical nature.