In Europe, North America, and especially New Zealand, farmers and foresters have even tried to make use of the powers of weasels for their own ends, particularly to control various “pest” species such as voles (small mouse-like rodents with short tails and small eyes and ears) and rabbits. But the philosophies of weasels and of people toward such situations are quite different: What for us is a problem, requiring elimination, is for weasels an opportunity, to be exploited. That is why biological control by weasels seldom works (Chapters 12, 13). One of the characteristics of a perfect tool is that it cannot be made to do a job.
