Air Force fights snakes from a plane

Two thousand drugged-up dead mice have been parachuted onto Guam near a US Air Force base. It’s not a bizarre training exercise, but rather an attempt to tackle an overpopulation of snakes.

The brown Treesnake is a long-standing problem on Guam. It’s not a native species and the most common theory is that it snuck inside an import shipment in the 1950s. Today it’s estimated there’s around two million snakes on the island, meaning something like 13,000 per square mile. The population growth is fuelled largely by the fact that between birds, lizards and rodents, Guam is effectively a buffet menu for snakes.

Not only is the Treesnake a significant threat to Guam’s bird population, but it’s also caused problems for the military: the snakes regularly slither into electrical substations and caused up to $4 million damage a year. Previous attempts to tackle the snakes with traps and dogs have proven impractical given the sheer number of snakes.

The new tactic takes advantage of the fact that the snake has a weakness: it finds acetaminophen highly toxic even in low doses. (Acetaminophen, known outside the US as paracetamol, is a painkiller that’s the major ingredient in the branded drug Tylenol.)

The project, supervised by the Department of Agriculture, involves filling dead mice with 80 milligrams of acetaminophen. These mice have then been attached to a crude parachute made up of cardboard and tissue paper, which allows it to float down at a slow enough pace that it should then get caught in trees without disintegrating.

The idea is that the snakes will then eat the mice and die around three days later. The dose is low enough that virtually no other creatures on Guam should be at any risk.

If the initial test goes well, the tactic will be rolled out as part of an $8 million program, something that sounds extravagant, but would pay for itself within two years.

It’s not the first time the military has spent money on snakes. Back in 2010, the Department of Defense funded a study into how several species of snake in South Asia are able to glide and/or fly between trees despite having no wings. The idea was to find ways to make unmanned aircraft that require less power than existing models.