The Atala butterfly (Eumaeus atala) and its five closest relatives in the genus Eumaeus like to display their toxicity. This sextet’s toxicity comes from what they eat as caterpillars: plants called cycads that have been around since before dinosaurs roamed the Earth and contain a potent liver toxin called cycasin.
Click here for original story, Scientists discover how a group of caterpillars became poisonous
Source: Phys.org