How do we enter the strange and fascinating world of small organisms? How do scientists explore their habits, growth, and rather intriguing behaviours? In this album, scientists from Italy, the US and the UK reveal some of the technologies and techniques they use to investigate the behaviour of small aquatic organisms such as flagellates, plankton and filter feeders. In the audio track, Dr David Robinson of The Open University talks about some of the problems and rewards of investigating very small aquatic creatures. This material forms part of The Open University course S204 Biology: uniformity and diversity.