The Rat Hunt activity introduced by French: 1. The French built large sewers in their area of Hanoi. The refuse of old city overflowed into the streets during rains and floods. 2. This became the cause of the bubonic plague as it became the breeding ground of the rats. The sewers also served as a transport system of rats. 3. When the plague spread to the hygienic houses of the French, they hired Vietnamese to kill the rats. The French paid for each rat and thousands were killed. 4. However, there seemed no end to the rats. This also brought the Vietnamese together to negotiate for a higher price. 5. The tails had to be shown as proof of clipping so many people just cut the tail and let the rat go so that it could be repeated. Some even started raising rats. The French removed the bounty-fed up of the people's resistance.