Took the kids to the National Zoo this morning for fun, but also got an inadvertent education. We learnt a few things. Most interesting: We saw 3 cheetahs, who were, we were told, brothers. The FONZ volunteer who happened to be wandering around, educating people about cheetahs, told us that although cheetahs have spots around most of their bodies, their tails have rings around them. And he told us that every cheetah's tail rings are unique, enabling us to identify each cheetah from every other cheetah.
I mentioned this to a coworker this afternoon. He looked at me, smiled and said, "Great, they are barcoded!"