The U.S. Air Force took to the skies over Guam on Sunday to shower death upon the invasive and troublesome brown tree snake. But instead of napalm, bombs, and mustard gas, planes released 2,000 dead mice, stuffed to the gills with deadly painkillers, which sailed gently down to the earth on tiny cardboard parachutes.

The dead mouse drop was the fourth and largest such operation, part of a $8 million program aimed at wiping out the snakes and saving Guam's endangered bird population. Officials also hope to save the estimated $4 million it costs annually to repair damages dealt to the island's power infrastructure by snakes working their way into power substations and shorting them out.

The snakes have been highly successful since they arrived on Guam in the 1950s, with a population now believed to be near 2 million. Officials have tried traps, dogs, and hunting programs, all to no avail. Fortunately, the snakes have proven highly sensitive to acetaminophen, the active ingredient in over-the-counter Tylenol. Just one-sixth of a pill is enough to lay a tree snake to rest.

So, thousands of mice are killed, stuffed with Tylenol, and rigged into their tiny parachutes for their final mission. "The cardboard is heavier than the tissue paper and opens up in an inverted horseshoe," assistant supervisory wildlife biologist Dan Vice told KUAM. "It then floats down and ultimately hangs up in the forest canopy. Once it's hung in the forest canopy, snakes have an opportunity to consume the bait."