The 'law of urination' says that all mammals - regardless of size - pee for 21 seconds!

Believe it or not, a group of scientists went to Zoo Atlanta to measure how fast animals peed.

They discovered that most mammals, regardless of size, pee an average of 21 seconds. This is despite a bladder-size range of 100mL to 100L.
They called this the "Law of Urination," and explain that mammals' urinary system evolved to eject fluids quickly and efficiently.

Larger animals have larger urethras, which amplifies gravitational force and flow rate. Urethras evolved as a flow-enhancing device, which enabled the urinary system to scale up without compromising function.