We might know mice as being quiet as well, themselves, but in reality, these little mammals have got a whole lot to say, and they've figured out how to say it a way that doesn't alter big oafs like us to their whereabouts. A new study by researchers at Duke University in the US has recorded male mice 'singing' to their prospective mates at frequencies we'll never hear without some technological assistance.

It's been known for years that mice sing songs to each other at ultrasonic frequencies, but until now, no one had made the effort to analyse all the different chirps, pips, twitters, and squeaks that make up these incredibly complex tunes. So the researchers at Duke, led by biologist Jonathan Chabout, recorded some males as they were faced with what they thought was the prospect of a female. (In reality, there were no females, just a waft of female urine, which means these poor males were trying to serenade pee.)

The inherent tragedy of the situation aside, the researchers found that when the scent of the female was present, the males sang a much louder and more complex series of songs, made up of intricate and repeating patterns, than when faced with an actual female. This suggests, the team writes in the journal Frontiers of Behavioural Neuroscience, that they're more willing to expend the extra energy to draw a mate closer.

"We think this has something to do with the complex song being like a calling song, and then when he sees the female, he switches to a simpler song in order to save energy to chase and try to court her at the same time," said Jarvis in a press release. "It was surprising to me how much change occurs to these songs in different social contexts, when the songs are thought to be innate," he added. "It is clear that the mouse's ability to vocalise is a lot more limited than a songbird's or human's, and yet it's remarkable that we can find these differences in song complexity."

Quiet as a mouse? Only to our sub-par human ears.