Massive bird die-offs in the US states of Arkansas and Louisiana have grabbed headlines around the world. Investigators don't know what caused the birds to die. Early theories blame fireworks from New Year's Eve celebrations or lightning. Others take the bird deaths as a sign that the End of Days are near. One group believes Judgment Day will arrive on May 21 (so mark your calendar). Still, others think a government program such as HAARP might be to blame. Gamers, however, see a simpler explanation: They were just angry birds trying to get their eggs back from the evil pigs.