Abstract This study investigated the association between tail biting (TB) and other abnormal behaviours in a group of non-tail docked pigs. Behavioural data were collected from 742 pigs housed on a commercial farm. The prevalence of performed and received TB, belly nosing, bar biting, ear biting and mounting was recorded during two 30min observation periods. Pigs were categorized based on the number of performed tail bites/hour; non-performers (NP, TB=0, n =643), low performers (LP, TB=1–4, n =79), high performers (HP, TB>4, n =20) and the number of received tail bites; non-receivers (NR, TB=0, n =559), low receivers (LR, TB=1–2, n =133) and high receivers (HR, TB>2, n =50). Based on the intensity of the receivers' response to being bitten, TB behaviour was further classified into three grades; no, mild or severe reaction. Tail-in-mouth behaviour, which did not involve biting, was also recorded. The proportion of performed bites classified as severe was significantly higher ( P P The three performer categories differed in the amount of performed tail-in-mouth ( P P P P =0.002; ‘other abnormal': 0.48±1.56, P The receiver categories differed in the amount of received ‘other abnormal' behaviours, for which HR (1.16±1.89) received significantly more than both LR (0.68±1.10, P P