Pipevine swallowtail butterflies get their unusual name from the fact that they lay their eggs on a variety of pipevine plants in the Aristolochiaceae family. These include pipevine, woolly Dutchman’s pipe, Texas Dutchman’s pipe and Virginia snakeroot, just to name a few.

The caterpillars that hatch and eat the leaves of these plants ingest a type of acid that makes them taste terrible to predators like birds. Adult pipevine swallowtails retain their acidic bad taste from their days as a caterpillar, and it continues to act as a great defensive mechanism.

It works so well that some other butterflies try to mimic the color pattern of pipevine swallowtails with the hope that hungry birds will mistake them for the pipevine variety and shun them, too. Some of those other species include the spicebush swallowtail, the red‑spotted purple, female black swallowtails and the dark morph of the female tiger swallowtail.