In this paper, we explore museum visitor learning through the examination of the engagement in narrative-making practices of school children while visiting a natural history museum. Two groups of children are given worksheets and encouraged to use their own mobile technologies to document their visits in relation to the subject of evolutionary mechanisms. Their engagement is occasioned through this worksheet and we show how they negotiate the interpretation of the task and then go on to complete it in quite different ways. We examine, in turn, how the students structure their visits with walking paths through the museum exhibitions, and how they structure the narratives they produce to complete the tasks by using the tools at hand and incorporating different parts of the exhibits.