“Any history, including the history of the development of life on Earth, is an intricate interweaving of causes and effects. Take away one thing, and everything else will change beyond recognition”—with these words and the famous example of a butterfly from a story by Ray Bradbury, paleoentomologist Alexander Khramov begins his amazing story about the six-legged owners of the planet. We brush away flies and mosquitoes, fight cockroaches, avoid anthills, not to mention lice! But if there were no lice, the person would remain as hairy as a chimpanzee. And in general, in the absence of insects, vertebrates would never come to land, since they would have nothing to eat there. Yes, there are many books about insects, but this is the first one that talks about them from the point of view of their formation and historical development. Paleoentomology is not mathematics, much of this rapidly developing science is based on hypotheses and interpretations, but thanks to the emergence of ever new data and research methods, scientists can share with us exciting discoveries and guesses, adding new fragments to the picture of the world. And the author does it with passion and talent.