In order to be able to help students to read nature and to get an ability to discern both biodiversity in different contexts and changes in the environment we need to investigate how they experience biodiversity and how they discern different components in an ecosystem. Therefore, we undertook an interview-study of fifteen 10-12 year old students’ experiences of biodiversity and how they discerned organisms in different ecosystems. We analysed how they described the organisms and how they referred to experiences from everyday life. After two years we interviewed the students about what they said in the initial interview. Experiences of biodiversity at an early age seemed to be important for the future development of their understanding. It is important, both to give children early experiences of biodiversity in nature and to take students’ early ideas into consideration in teaching for lifelong learning and for a sustainable future.