Tail biting in pigs has been an identified behavioural problem for decades. It has serious economic consequences for pig producers, and animal welfare implications for both the individual expressing this abnormal behaviour and the victims of the activity. The inability to prevent occurrence of the behaviour reliably under commercial farm conditions has resulted in the majority of large pig enterprises throughout the world considering it necessary to dock the tails of all piglets as a preventative measure. This, in itself, constitutes both an animal welfare and an ethical issue, as highlighted in the EU Directive 91/630 on pig welfare which constrains routine tail docking and emphasises the need to find alternative preventative strategies.