Actions studied by ethologists that appear out of context or irrelevant to the situation, such as scratching movements or self-grooming behavior during anxiety, conflict, embarrassment, frustration or stress. Sometimes interpreted as a defence mechanism, involving motivational disinhibition, and in non-humans as an instinct. In contrast to displacement activity, there is redirected activity: actions directed away from the main target and to another less appropriate target, and thus unlike displacement is a substitution in the kind of interrupted action.