The present invention relates to formulations useful for affecting the behaviour of mosquitoes. More specifically, the present invention relates to formulations for activating mosquitoes such as for attracting mosquitoes. The present invention further provides methods and dispensers incorporating these formulations. The formulation comprises a thio compound as the active, preferably a thioether such as allyl methyl sulphide (AMS), 1-methylthio-propane, 3-methylthio-propanol (MTPL), (E)-1-methylthio-1-propene, (Z)-1-methylthio-1-propene, or derivatives thereof.
