In 1935 hundreds of cane toads were brought in Australia from Puerto Rico in the hope that they will destroy pests of sugar cane. In theory, food and natural enemies regulate the number of each population. But in the case of frogs, it turned out that there is more than enough food for them, and there are practically no natural enemies. It is not only that they do not eat sugar cane pests, there appeared as many toads as locusts in Biblical times, and there are no effective ways of dealing with them. Practically, toads invade Australia.