*Do not throw rocks at the crocodiles to see if they're alive. The answer will quickly end up being 'well, not NOW they're not'.
*Do not throw rocks at the elephants either. They can throw harder than you can.
*Do not throw snowballs at the lions.
*Do not feed the-- actually, you know what? You may actually want to feed the Siberian tigers, because the zookeepers aren't.
*In fact, bring money if you want to do that, because for a reasonable fee, they will hand you the live animal to toss screaming into the cage yourself.
*Or, well, wait long enough and the problem might just take care of itself.
*Please be mindful of where the tiger-bone liquor came from.
*Be sure to take a picture of yourself with the panda bear. That might be how it gets fed.
*Please be respectful of the mass animal grave you may inadvertently be near.
*Please bring the elephants a space heater.
*Do not teach the myna birds bad words.
*Do not give the chimpanzee a cigarette no matter how much he begs. Or a beer, for that matter.
*If you must go see a chained monkey ride a bicycle while a tiger rides horseback and a bear rides the high wire on a motorbike, do be careful as that's been supposedly outlawed.