New Scientist said:
You'll never look at Dumbo in the same way again. Elephants, cows, goats and dogs all take roughly 21 seconds to empty their bladders. A "law of urination" now explains the physics behind what happens when you just gotta go.
Patricia Yang and colleagues at the Georgia Institute of Technology in Atlanta use high-speed video to study how fluids and animals interact; they have previously investigated how dogs shake themselves dry.
While filming at a local zoo, they noticed that animals of various sizes, both male and female, took a similar time to empty their bladders.