A pioneer named Thomas Austin brought the rabbits from England to his property in Australia for hunting. The rabbits reproduced so fast that 10 years later, 2 million rabbits were being shot annually without making a dent in the population. It was the fastest spread ever recorded of any mammal anywhere in the world.
The rabbits have devastated crops and native plant species, killed young trees in orchards and contributed to erosion by digging up topsoil. The rabbit problem has gotten so bad that Australians have resorted to using poison, bulldozers, and ferrets to keep the population at bay.
On the plus side, during the Great Depression there was always a readily available food supply.