The Scottish midge is a small beast with a big reputation. As one of the few flies in the British Isles that feed on human blood, it can cause havoc for anyone who has to live and work among them. But what makes some of us more attractive to the midge than others? On a journey around some of Scotland's midgier places, insect scientist Dr James Logan of the London School of Hygiene and Tropical Medicine explores the secret life of the midge to discover how best to cope with the terror of the Highlands and whether some of us might contain our own natural midge repellent.