Academia Nuts: Bats win peeing contest

Experts at the Georgia Institute of Technology in Atlanta have clocked the pee-time of rats, dogs, elephants, goats, and cows, and come up with a "law of urination"—that each animal takes about 21 seconds. Elephants empty their bladders at the same speed as smaller mammals, because gravity pulls urine quickly through their large urethras. Smaller animals, on the other hand, have shorter urethras that get less gravitational pull, but smaller bladders to empty out. Still, the urinary law has its limits: Really small creatures like bats and rats can pee in less than a second.   More       [BJS]