A gorilla escaped from his exhibit last week at the Dallas Zoo and attacked three people before being shot to death by police. Now zoo officials say two teen boys were seen throwing rocks or ice at the gorilla shortly before he escaped. They speculate the taunting may have made the gorilla angry enough to find a way past 12 to 16 foot walls, moats, and electrified wires. The lesson here: don’t perturb a primate.