Pheromones are chemicals substance produce and released into the environment by an animal, especially a mammal or an insect, affecting the behavior or physiology of others of its species. Pheromones are divided into two types: Releaser and primer pheromones. Releaser pheromones are the chemical signals by one animal that, when detected by another animal of the same species, cause it to immediately perform a set of behaviors. The fear scent that induces spontaneous scattering of ants would be an example. Also when the secretion of a male pig’s saliva that cause a female in heat to assume a submissive copulatory position. Primer pheromones are the chemicals signals that induce more long-term physiological changes in the receiving animal. The secretion of female fish that stimulates sperm production in males constitutes a prime pheromones, as does the chemical that induces the aforementioned menstrual cycle synchrony in cohabitating mice.
There have been claims by the fragrance industry that synthetic pheromones can change our sexual behavior. There is no scientific evidence that support all these claims. There is one possible human chemical signal that could act as a single pheromone. New infants are able to tell the smell of there mother’s based on the secretion from the gland around the nipple. Research on these infants suggests that the odors of a mother’s nipple can induce an automatic behavior in her infant. How we typically evaluate human and animal behavior has led some researchers to a revised definition of pheromones.