Pictured here is a female Black Swallowtail butterfly feeding on a young dandelion bloom. Note the band of iridescent blue along the hind-margin of her wings bordered by yellow spots. You also can see the two rearward projections from the hindwing for which they are named.
In this image, you can see the large orange spot on the hindwing with a black spot in the center. This character along with its surrounding colors help identify this individual as a female Black Swallowtail, Papilio polyxenes. Members of the Swallowtail family (Papilionidae) can be found throughout the world and are over 500 species in number.
Here you see the same female feeding on Henbit. Many members of Papilionidae use mimicry to protect themselves from predation. By looking like another species that predators learn is distasteful or will make them vomit, the mimic gains protection from being eaten. The Black Swallowtails coloration mimics the Pipevine Swallowtail which stores noxious chemicals from the plants their larvae eat which deters predation on themselves and their mimics.
In the final image, you can see that despite the size of her perch and a small gust of wind, she is able to maintain her balance on the flower and continue to feed by flapping her wings.
For more information on these and other butterflies, you might like to visit the Butterflies and Moths of North America website, or The University of Florida Department of Entomology and Nematology website, or Will Cook’s website on the living things found in North Carolina. You can also visit another of my posts for another pretty example of this species.