A better option is to simply set the reward lower than the marginal cost of raising the snakes or other pest to begin with. So that there is a benefit to killi

A better option is to simply set the reward lower than the marginal cost of raising the snakes or other pest to begin with. So that there is a benefit to killing and turning in one that is encountered but not for a primary enterprise - the real problem is lack of both economic understanding and long term thinking on the part of bureaucrats.