In terrestrial vertebrates, the sense of smell provides important information about the environment and enables the animals to detect food, avoid predators, and find mates.  Odors are detected by the sensory neurons in the olfactory epithelia in the nose, which pass the information to the main olfactory bulb (MOB) for further processing. Pheromones, a set of chemical signals emitted by the animals for intra-species chemo-communication, convey information about the sexual, social, and reproductive status of other individuals. Pheromones trigger a restricted repertoire of innate and stereotyped behaviors such as mating rituals, territorial aggression, and neuroendocrine responses. Pheromones are detected by their receptor neurons in the vomeronasal organ (VNO), which project axons to the accessory olfactory bulb (AOB).