Ultrasound production by the long haired rat of Australia (Rattus Villosissimus)

The ultrasonic vocalizations produced by the long haired Australian rat Rattus villosissimus, during agonistic behaviour were investigated using a commercial ultrasonic receiver with earphones, a microphone and storage oscilloscope, and a tape recorder and sonograph. The rats were found to produce one audible call with ultrasonic components up to 64 kHz, the limit of the detecting apparatus used, and one pure ultrasound. Suggestions are made as to their behavioural significance.