Darwin's ant conundrum (IMAGE) Arizona State University Caption Even Charles Darwin threw his hands up in the air when trying to explain one species of dulotic ant in his “Origin of the Species” book. “By what steps the instinct of F. sanguinea originated I will not pretend to conjecture,” wrote Darwin. This is his original sketch of a parasitic Formica ant raiding the pupae in a rival nest. Credit On the Origin of Species Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.