Rats of the World Unite

Bali had a rat problem. Rats were eating the stored gran that had been shipped to the country to aid after a hurricane had destroyed much of the standing crop. The government put a bounty on rates to encourage the citizens to kill them. The rat population sharply declined as people set out to get the bounty. Then the numbers of rats suddenly shot up as the citizens bean to raise rats for the bounty. After all, breeding them was much easier than catching them.