There are living things so tiny millions could fit on a dot. Although they are invisible, they are everywhere and they multiply very quickly. They are vital for life on earth, and do all sorts of things – from giving us a cold and making yoghurt to wearing down mountains and helping to make the air we breathe. With charming illustrations by Emily Sutton, this friendly, clever book by Nicola Davies succeeds in conveying the complex science of micro-organisms simply and clearly, and opens up an exciting new avenue for young non-fiction.