Quiet as a mouse? No way, listen harder

Spooked by a looming bird flu outbreak and ready to throw out your pet songbirds? Try keeping mice instead. Apparently they sing like birds.

All right, the typical male mouse vocalises at too high a pitch in ultrasonic frequencies to be heard by the human ear. But two scientists in the US, Timothy Holy and his partner from the mainland, Guo Zhongsheng, have developed a software that can shift the pitch to fall within our hearing range.

'The first time I played it back, it was pretty surprising: it sounded so much like birdsongs,' Dr Holy told Nature, the science weekly.

However, it takes a bit more work to get male mice than birds to perform their ultrasonic love songs. The two researchers at Washington University School of Medicine in St Louis, Missouri, had to collect female mouse urine to entice the males to serenade.

The pair hope to test next whether mice learn to sing from one another, or they do so instinctively. If it is a learned behaviour, then they are exactly like birds and humans, rather than cicadas, which instinctively produce clicking sounds to court potential mates.