Sounds Like Pounding the Flounder

A tiny insect has proved that size really doesn't matter - by using its penis to become the loudest creature on Earth.  Most would think the 2mm long water boatman would not have much to shout about, seeing as its private parts are thinner than a human hair.  But its looks have proved deceiving as it can reach an ear-splitting 99.2 decibels by rubbing its penis against its abdomen - which, relative to its body size, makes it the world's most boisterous bug.  

The water boatman, or Micronecta scholtzi, has been dubbed 'the singing penis' for the way it serenades potential mates.  Found all over Europe, the male tries to seduce prospective partners by rubbing its member against its abdomen, while underwater, in a process known as stridulation. 

It is so loud that humans walking along a river bank can hear the noise coming from the bottom of the water.  But as 99 per cent of the sound is lost when transferring from water to air, it means there is no risk of deafening passers-by.  Their average song reaches 78.9 decibels, the same as a passing freight train.

French and Scottish scientists made the startling discovery that at just 2mm long, the water boatman is the noisiest animal on Earth - once body size is taken into account.  Researcher Jerome Sueur, from Paris' National Museum of Natural History, was analyzing the biodiversity of French streams when he heard the distinctive underwater call.  At first he believed a much larger insect was responsible for the racket, but when he caught them they did not make the same sound.  Further investigation revealed it was a particular type of water boatman that was 'singing' its heart out.

James Windmill, of the University of Strathclyde in Glasgow, said: "We were very surprised. We first thought the sound was coming from larger aquatic species.  When we identified without any doubt the sound source, we spent a lot of time making absolutely sure that our recordings of the sounds were calibrated correctly.  If you scale the sound level they produce against their body size, then they are the loudest animals on Earth."