What kind of animal is the "Three Rs"?

Fifty years after the publication of The Principles of Humane Experimental Technique by Russell and Burch, this paper explores the contemporary role of the Three Rs. This is illustrated by reference to a recent social scientific study, which involved a total of 50 in-depth interviews with scientists who use animals and with other stakeholders in the debate. The data analysis shows how the Three Rs are conceptualised in at least three ways: firstly, as an ethical animal, either as a shorthand for a moral imperative, or as a route to managing an ethical dilemma; secondly, as a scientific animal, internal to the scientific method; and finally, as a political animal, with some stakeholders referring to the Three Rs as a way to promote consensus in a controversial domain. Pushing the metaphor a little further, the paper concludes that the Three Rs concept has become a kind of hybrid animal.