Humans brought the brown tree snake to Guam about 60 years ago. Since then, the reptiles have slithered their way across the island — devouring whole bird species as they went. The snakes are such a threat to bird life on Guam that authorities have decided to resort to drastic measures. Beginning later this spring, they'll drop an armada of painkiller-spiked dead mice onto the island. One tiny parachute per mouse. The hope is that snakes will eat the mice and OD on painkillers. This is not a joke.