Male mice communicate more in front of an audience than when they are alone.
Mice live in large social groups and communicate using ultrasonic frequencies. To learn how this social environment influences their vocalizations, Roian Egnor of the Howard Hughes Medical Institute's Janelia Research Campus in Ashburn, Virginia, and her colleagues exposed male mice in the lab to a female odour. They then compared vocal responses from animals that were alone to those that were in the presence of another male. Males that had an audience produced vocalizations that were longer and more complex than those from solo males.
The male mice could be communicating to other males to compete for mates, the authors suggest.