Hunting the brown tree snake on Guam
8 May 2012 Last updated at 22:08 BST
The tiny US territory of Guam is packed with more than two million brown tree snakes.
The serpents first arrived on the island 60 years ago from Papua New Guinea. But they so rapidly grew in number that they are now one of the worst invasive species in the world and have decimated the local wildlife.
BBC science reporter Rebecca Morelle joins wildlife biologist James Stanford on the trail of the snakes.
Produced by Rebecca Morelle and Simon Hancock.