Sensing the chemical warnings present in the environment is essential for species survival. In mammals, this form of danger communication occurs via the release of natural predator scents that can involuntarily warn the prey or by the production of alarm pheromones (APs) by the stressed prey alerting its conspecifics. Indeed, in a threatening situation, mice alert their conspecifics by secreting APs. In the recipient animal, APs are specifically recognized in the nose by an olfactory subsystem, the Grueneberg ganglion. They induce an increase in corticosterone levels and stereotyped innate behaviors such as freezing. However, APs structures still remain elusive. We have investigated by chemical methods (SPME-GC/MS) and physiological approaches (calcium imaging, behavioral studies) the volatiles emitted by mice under dangerous situations. We have now identified a mouse alarm pheromone, the SBT that interestingly shares structural similarity with the mouse predator scents such as for example the ones found in fox and stoat. Thus, our recently published paper in PNAS, not only reports the first mammalian APs identification but also points to a biological strategy called "chemical crypsis". Indeed, this olfactory strategy allows the modification of the own scent, in order to be hidden from the danger and to communicate its presence in an altruistic way to conspecifics.