Any form of behaviour associated with aggression or submission, including threat, attack, appeasement, flight, predation, or avoidance of predation. Agonistic behaviour between members of the same species generally involves a mixture of aggressive and submissive tendencies. It is often associated with defence of a territory; for example, a threat display by the defending individual is often met with an appeasement display from the intruder, thus avoiding harmful conflict. In contrast, predatory behaviour does not involve conflicting tendencies of aggression and submission: the predator is motivated by hunger, and the behaviour of potential prey is motivated by the imperative to survive.