Georgia  - A study showing that nearly all mammals take the same amount of time to urinate has been awarded one of the 2015 Ig Nobel prizes at Harvard University. These spoof Nobels for “improbable research” are in their 25th year. The team behind the urination research, from Georgia Tech, won the physics Ig. Using high-speed video analysis, they modelled the fluid dynamics involved in urination and discovered that all mammals weighing more than 3kg empty their bladders over about 21 seconds.

Their subjects included rats, goats, cows and elephants - and although the findings reveal a remarkably consistent “scaling law” in bigger beasts, they also emphasise that small animals do things quite differently. Rats can urinate in a fraction of a second, for example.

This might make rodents a poor choice for studying urinary health problems.

“We don’t have a proper animal model for urinary system research,” said the study’s lead author Patricia Yang, a PhD student in mechanical engineering. She told the BBC there might also be physical lessons to learn, from the adaptability of the system in bigger creatures. From water towers to drinking backpacks, Ms Yang said, “every time we need a new function, we figure out a new design for it.

“But in nature, they just have one system for all different sizes. This might inspire us - we could have a scalable design that fits different purposes.” Ms Yang and three colleagues published their findings in the journal PNAS last year, and on Thursday all four researchers were present to accept their prize at the Ig Nobel ceremony.

Run by the science humour magazine Annals of Improbable Research, this is a jubilantly irreverent affair. It has become world famous for recognising scientific achievements that “make people laugh, and then think”. This year’s Ig winners travelled from six continents to accept their trophies. The triumphant research included a chemical recipe to partially un-boil an egg, and the discovery that the word “huh?” occurs in every human language.