We teach teens what we think they ought to know, and we never tell them what they want to know.
I mean, first, almost all writers these days teach because they don't make enough money publishing to live on, to support themselves - people like Tobias Wolff, Anne Beattie, Amy Hempel, Stuart Dybek; a lot of short story writers, for one thing.
In this day and age when we do so much business in foreign trade, we need the ability to identify trace an animal very quickly, identifying where it came from - where it has been, and where it is at today.