To date, more than a million insect species have been described, with probably at least another 5-8 million species waiting in the wings for a name. Insects are a fascinatingly diverse and beautiful spectrum of animals. They range in size from the tiny parasitic wasp, measuring a mere 139um, to the aptly named Titan beetle, which can reach lengths of up to 17cm. They can be found on all continents of the world, from the Sahara Desert to the frozen wastes of Antarctica; in caves, under the ground, inside plants, other insects and vertebrates, in rivers, streams, lakes and ponds, in puddles, in the watery interiors of pitcher plants; and in our houses. While no insects live beneath the waves, the intrepid sea skaters skim the surface of some of the world's oceans. This Very Short Introduction explores the extraordinary world of insects. It analyses insect evolution, taxonomy and development, and describes their behaviour, their life styles, and the interactions they have with other insects and other animals. As Simon Leather shows, insects are the bedrock on which human civilisation rests; without them we would almost certainly not exist. Although they can be seen as pests of our crops plants, they are also invaluable for pollinating our flowering plants and are an invaluable link in all land ecosystems. As they face challenges from climate change and pesticides it has never been more important to understand these oft-dismissed creatures. Very Short Introductions: Brilliant, Sharp, Inspiring ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable. Introduction 1. In the beginning 2. Prolific procreators - reproduction and host selection 3. On the move - finding somewhere to live and something to eat 4. Living together - social insects, parental care, mutualism 5. Aquatic insects - skaters, divers, and bottom dwellers 6. Mimicry, crypsis, and blatant advertising 7. Against the odds - behaviour and survival in extreme conditions 8. The good, the bad, and the ugly - how insects help and hinder us 9. Ecological Armageddon - insects in decline? References Further Reading Index Simon Leather is Professor of Entomology in the Department of Crop and Environment Sciences at Harper Adams University, where he leads the newly launched Centre for Integrated Pest Management. In the past he has worked at the Forestry Commission Northern Research Station and also Imperial College London, with a focus on agricultural and forest entomology. His books include The Field Course Handbook, (2021, co-authored with Tilly Collins and Patricia Reader).