The Peruvian metalmark butterfly plays the long con on its hosts. (The metalmark attribution refers to small metallic-looking spots commonly found on the wings of these mostly Neotropical butterflies.) As a caterpillar, the butterfly cooperates with ants, winning them over with sugary secretions. In return, the ants defend the caterpillar from predators.
When the caterpillar becomes a butterfly, it turns on its protectors: plundering the ants’ carefully tended nectar supply, which is harvested from bamboo shoots that pay for protection with sweets.
Ants usually fiercely defend their favored food source. The metalmark butterfly, which smells like its benevolent younger self, is an exception. The duped ants get nothing in return.