In Arkansas, thousands of blackbirds mysteriously fall to their deaths in an event now called the "Aflockalypse." What led these birds to flee their trees in what looks like a nighttime suicide mission? In Scotland, a clear slime catches scientists' attention. The substance lacks the DNA needed to connect it to life on earth; could it be cosmic? Hear from recent shark attack victims about the rise in the number of attacks. If people aren't a deliberate target, what's motivating them to attack?