There is another story I have heard many times about how the Vietnam government paid local people to kill rats. To prove they killed a rat, the locals had to cut its tail off and bring it in to collect payment.
The locals decided it was getting harder and harder to find rats to get paid to capture. They started to cut the tails off and release the rats back into the sewers so that they could procreate.
So the government's attempt to kill all rats ended in rats being bred and eventually an increase in rat population.
Here is one link that tells some of the story: