Why do woodpeckers not get headaches? What is it about the sound of fingernails drawn across a blackboard that makes us wince? And do the people who hand out university research grants have too much money at their disposal?
These were some of the questions answered at this year's Ig Nobel Awards ceremony, held at Harvard University on Thursday night. Organised since 1991 by the Annals of Improbable Research, the "alternative Nobels" recognise excellence in quirky and/or worthless scientific research.
This year's winners included the inventor of a teenager-repellent device (in the "peace" category); the authors of a study into why dry spaghetti often breaks into more than two pieces when bent (physics); and, for medicine, a case report called Termination of Intractable Hiccups with Digital Rectal Massage.
In the literature category, there could only have been one winner: Daniel Oppenheimer, for his paper, Consequences of Erudite Vernacular Utilised Irrespective of Necessity: Problems with Using Long Words Needlessly.
But not all were beyond practical application. Howard Stapleton's teenager-repellent device, the Mosquito, emits a high-frequency, siren-like noise that is painful to the ears of teens and those in their early 20s, but inaudible to those older.
The device exploits an ageing effect that means our ability to hear high frequency sounds wanes as we get older.
In our teens, we can typically hear sounds ranging from 20Hz to 20kHz, but with age the highest frequencies we can hear drops - sometimes to 18kHz or less.
"We discovered that, even at relatively low volumes, the right frequency noise would only be heard by 25s and below and it was highly annoying after five minutes," Mr Stapleton said. "The Mosquito was born."
Mr Stapleton's company has sold more than 2,500 units in 18 countries. And almost half have been bought by police forces, who use it for that perennial duty of authorities everywhere: getting the youths to move along.
The work on nails and blackboards, too, was part of a larger, legitimate project on frequency levels carried out 20 years ago by Vanderbilt University psychology professor Randolph Blake and two colleagues. What started as a small gathering in 1991 is now an international event, with winners travelling from around the world to attend.
The 2006 Ig Nobel ceremony ended with the traditional call from organiser Dr Marc Abrahams to researchers everywhere: "If you didn't win an Ig Nobel prize tonight - and especially if you did - better luck next year."