At the end of WWII, a single pregnant brown tree snake stowed away on a military transport from Papua New Guinea to Guam. 65 years later, two million snakes are eating everything on the island that moves, and the USDA is trying to fight them off by parachuting dead mice stuffed with aspirin out of helicopters.
The brown tree snake, being only mildly venomous, isn't much of a threat to people. It is much of a threat to just about everything else. The snakes wiped out 10 out of 12 native bird species in the wild, starting with eggs and moving right on to adult birds. When the birds were gone, the snakes started in on rodents, and then other reptiles and small mammals. They even crawl over power lines, regularly causing what the locals call "brownouts."
The U.S. Department of Agriculture has a long-term goal of completely wiping out ever last brown tree snake, and to make this happen, it's employing some, uh, rather bizarre strategies. One of the strangest is cramming dead mice full of aspirin (which is lethal to the snakes) and then dropping them out of helicopters attached to streamer parachutes. The parachutes get tangled up in trees, providing an easy (and last) meal for the arboreal snakes.
It sort of seems like dropping zombie mice from helicopters one at a time is maybe not the most efficient or cost-effective way of tackling an evil army of millions of snakes, but I guess the USDA is getting desperate. And it's not just Guam that's the problem, either: if these snakes make it to Hawaii, it would decimate the ecosystem to the tune of $400 million dollars. So that settles it, then: zombie mice away!