The dreaded brown tree snake on Guam has become so pernicious that officials have taken to dropping poisoned mice, equipped with parachutes, out of helicopters to try to kill the snakes, the BBC reports.

The snakes, which Hawaii government officials fear will migrate here through air or shipping cargo, have decimated wildlife, making the forests “eerily quiet.” And residents lose power so often from the snakes crawling on electric lines that locals now call the outages “brown outs.”

If the snakes spread to Hawaii, it could cost the state $400 million, according to the story. 

Read the full account here.