Robert Hooke's Micrographia, published in 1665, was the first major scientific work to use microscopic illustration systematically and included a spectacular full-page engraving of a flea magnified many times, revealing its armoured, alien appearance in astonishing detail. The illustration was an immediate sensation in London and caused readers to look at one of the most familiar and despised of human parasites with entirely new eyes. Samuel Pepys described reading the book as 'the most ingenious book that ever I read in my life.'

Hooke's flea engraving transformed the cultural status of the parasite by making the invisible visible, revealing the extraordinary complexity and beauty of a creature universally regarded as a pest. The revelation that the flea — Donne's erotic and philosophical toy — was also a miniature armoured beast sparked literary reflection across the century. Jonathan Swift's later parasite chain poem drew explicitly on the world of microscopic revelation that Hooke had opened, and the tradition of finding grandeur in the minute that runs through Romantic and later poetry owes something to the magnified flea of Micrographia.