Rabbits. Australia's largest rabbit population is also considered to be the most powerful, in the peak of the number of these rabbits reached 10 billion, a huge number of rabbit groups will be the local vegetation to chew a clean. Australia's livestock industry is also very developed, known as the "sitting on the back of the sheep country", these rabbits also let the livestock industry suffered serious losses.
Camel. What happens when camels are overrun? The camel is the "boat of the desert" in our eyes, is the best use of transportation in the desert, the British first arrived in Australia felt the environment is very harsh, so they used camels as a means of transportation, the introduction of nearly 10,000 camels. But soon the industrial age came and cars and trains replaced the camels, which were abandoned in the wilderness.
Cane toads. People in Australia seem to prefer the method of tearing down the east wall to repair the west wall, for the flooding of rabbits introduced the natural enemy of rabbits, foxes, and as a result, the fox population flooded along with the rabbits. Farmers in Australia chose to introduce cane toads, which eat sugar cane grubs, in order to eradicate the grubs, but the results were less than stellar.