A new research has revealed that all animals take same time to urinate, i.e. 20 seconds. The time to empty the bladder is same for all the animals regardless of their sizes. For example, an elephant's bladder is 3,600 times larger than a cat's bladder, but they both take same amount of time to urinate.

The researchers said the strange finding is likely to help engineers understand how nature uses gravity to regulate flows of liquid. The team of researchers claimed that all animals weighing more than three kilograms take same amount of time to urinate.

The flow rate of fluid is higher in larger animals because of the longer urethra compared to smaller animals, said David Hu, the Georgia Tech assistant professor who led the study.

An elephant has the one-meter-long urethra. The pressure of fluid in it is equivalent to what is at the bottom of a swimming pool three feet deep.

If the size of elephant's urethra was less, then it would have taken a longer time to urinate. The findings have dispelled the previous belief that bladder pressure generated by muscular contraction is responsible for controlling urinary flow.

The details of the study have been reported in the Proceedings of the National Academy of Sciences (PNAS). Hu and graduate student Patricia Yang derived a conclusion from their study that larger animals are able to empty their bladders in jets or sheets of urine because of gravity.

Length of urethra plays a key role. The effects of gravity on small animals are minimal. "They urinate in small drops because of high viscous and capillary forces. It's like peeing in space. Mice and rats go in less than two seconds. Bats are done in a fraction of a second", said Yang.