With its long ears, twitching nose, and adorable hopping ability, the individual rabbit is fairly cute. Multiply that bunny by millions, however, and they begin to seem entirely sinister. The great Australian rabbit infestation was ecologically devastating. The buck-toothed creatures helped extinguish nearly one-eighth of Australia’s native mammal species and led to the extinction of countless numbers of plants, leading to widespread soil erosion. The Australian government tried to corral the rabbits by building so-called rabbit-proof fences across vast stretches of land. Undaunted, the rabbits burrowed under. Finally, in the 1950s, the Australians resorted to chemical warfare, injecting several rabbits with myxoma, an experimental virus known to target and kill rabbits. The virus spread, and the rabbit population dropped from six-hundred million to one-hundred million. But that’s still a lot of rabbits, and those with a natural resistance to the virus began breeding with a fury. And so the rabbit wars carry on still.