The purpose of the model is to gain more insight in the causation of tail biting behaviour in group housed pigs. The model simulates the patterns of tail biting behaviour and the distribution of pigs into four tail biting categories: neutral (not involved in biting incidents), biter, victim, or both biter and victim. Tail biting behaviour can emerge when the internal motivation of pigs to explore cannot be fulfilled. The effect of a redirected exploratory motivation, behavioural change in victims and preference to bite a lying pig on tail biting patterns can be tested in the model.