This investigation shows that olfactory learning can be involved with food identification. An experimentally induced food preference can be obtained by presenting a scented food to newly hatched workers ofLasius niger(L.) (Hymenoptera Formicidae). Ten colonies were followed from their foundation. From the emergence of the first workers, the colonies were fed with a flavoured (anise) sugar solution (0.5M sucrose) during 1 month. After 3 months of hibernation without food, the colonies were submitted lo a choice test. The preference for the scented food indicates the existence of a “pre-hibcrnal learning” process with long term effects. Older foundations which were exposed to the flavoured food after the 3 months hibernation period preferred the known food, but the preference was less strong than that shown by the first group. Finally, mature workers from adult colonies, submitted to the same treatment, did not respond to the olfactory cues and exhibited no food preference. These results suggest the existence of an early learning period for food odour.