As nocturnal animals, mice rely on the chemical substances called pheromones to share personal information with other rodents. Age, gender and general state of health are all determined by the sniff of a whiskery nose.

Researchers now say they have discovered a pheromone that young mice use to ward off sexual advances from older ones. By secreting the pheromone through their tears, prepubescent mice can inhibit the mating behaviors of adult males, according to the study, which appears in the journal Nature.

The pheromone, ESP22, activates neurons in the vomeronasal organ, a part of the olfactory system also known as Jacobson’s organ. The response blocks sexual advances toward the animal producing ESP22.

When the researchers disrupted either the organ or the production of the pheromone, the older mice displayed increased mating behavior toward the juveniles. The researchers found no response to the pheromone in females, though they haven’t ruled one out.