The following article reports on a small-scale, exploratory study of aggressive and "problem" behaviour in pre-school children. This project was conceived in the wider context of anxieties about childhood and New Labour's policy focus on "anti-social" behaviour in children. Based on interviews with nursery staff and parents in addition to participant observation undertaken in nursery playrooms, this article examines the relevance of time, space and gender for understanding problem behaviour in young children. Taking a social constructionist perspective and drawing on Foucault's ideas in particular, it examines the social processes which regulate and normalise behaviour in young children.