Brown Tree Snake
The Brown Tree Snake, Boiga irregularis, is an arboreal colubrid snake native to eastern and northern coastal Australia, Papua New Guinea, and a large number of islands in northwestern Melanesia. This is a nocturnal snake and is rarely seen by humans in its habitat.
The snake is considered a pest in Guam where it is not native. It was carried there on a US military transport at the end of WWII. The slightly venomous, but rather harmless, snake killed almost the entire native bird population on the previously snake-free island. As the snake has few predators on the island, Guam now has the highest snake density in the world. It is estimated that there are about 2000 brown tree snakes per square kilometer on the island.
At least 8 brown tree snakes have now been found in the Hawaiian Islands as well. Because they can be as harmful there as they were to Guam, the State of Hawaii makes concerted efforts to inform the public about the snakes.