As they felt that they weren't making enough progress and due to labour strikes they created a bounty programme that paid a reward of 1¢ for each rat killed.[1] To collect the bounty, people would need to provide the severed tail of a rat. Colonial officials, however, began noticing rats in Hanoi with no tails. The Vietnamese rat catchers would capture rats, sever their tails, then release them back into the sewers so that they could produce more rats.[2]
Ayaaaa, les français n'étaient pas ready pour le QI à 3 chiffres des viets