In order to mate, male moths must find a female by flying or walking upwind, tracing a stream of dilute pheromones in the air. Recent research attempting to understand how information about the pheromones is processed in the olfactory neural system of the brain and how this information participates in generating and controlling orientation behavior, provides useful insight. The present review concerns with overview of odor orientation behavior and olfactory processing pathways of an insect brain, focusing on state-dependent of flipflopping neural sig- nals to repetitive pheromonal stimulation, which are important in controlling the behavior.