Common flea (Pulex species): adult, pupa, larva and egg. Engraving by M. Griffiths, ca. 1805. https://www.rawpixel.com/image/13974094/image-cartoon-pattern-animalFree Image from public domain licenseAbdominal anatomy of the horse shown with examples of gadflies: six figures showing the kidneys, bladder and large… https://www.rawpixel.com/image/13998126/image-paper-butterfly-heartFree Image from public domain license