Chiroptera–Fledertiere from Kunstformen der Natur (1904) by Ernst Haeckel. Original from Library of Congress.… https://www.rawpixel.com/image/2272418/free-illustration-image-bat-ernst-haeckel-plagueFree Image from public domain licenseSix nocturnal mammals of the order Chiroptera. Line engraving by Milton after S. Edwards. https://www.rawpixel.com/image/13961449/image-paper-cloud-cartoonFree Image from public domain license