Apidologie - A bee in front of an odor gun. This technique allows for an association between an odor and a sugary reward. A sweet solution is applied to the antennas and the bee stretches out its proboscis, its little trunk. This odor-reflex association has brought to light the bees' capacity to remember odors and the time necessary to acquire olfactory memory. But also more complex learning: for example, an odor A is associated with a sugary solution and an odor B is not. Then, shortly after, it is reversed: the odor A is no longer associated with sugar but the odor B is. Result: the bee is capable of replacing the first signal by the new one. Paul Sabatier University, CNRS, Toulouse, France