Traditionally, game-keepers and agriculturalists have controlled predators using lethal methods, but there are circumstances under which these may be ineffective or inappropriate for animal welfare or conservation reasons. Generalised aversion is potentially a form of non-lethal control,
in which predators are conditioned to avoid foul-tasting bait, causing them subsequently to generalise this avoidance to similar, but untreated, prey, thereby affording it protection. In this exploratory study, a group of captive red foxes (Vulpes vulpes) was successfully conditioned
to avoid untreated milk after drinking milk containing Bitrex™, a bitter substance that they were unable to detect except by taste. Our foxes were members of a family group and so housed together to reduce stress, and therefore the individuals' responses to the various treatments
may not have been independent. As a result, we combined data from the three animals, and our most conservative analyses consider the sampling population to be this fox group; we do not make inferences about foxes in general, but confine them to this fox-group. This trial was a pilot to reveal
the potential for future work on wild animals. Successful application of generalised aversion to non-lethal predator control has far-reaching implications for the sport hunting industry, nature reserve management and the conservation of threatened predators requiring control, as well as clear
animal welfare benefits.