The Red Admiral butterfly (Vanessa atalanta), one of four different butterflies in the Vanessa genus, can be found in fields, forests and cities around the United States.
Contrary to the name, they do not belong to the Limenitidinae subfamily of Admirals and their relatives, however, the red stripe on the forewing show a resemblance to the stripes in Admiral butterflies. See the Lorquin's Admiral for an example.
The caterpillars feed on plants in the nettle family, a very common group of plants. Rotton fruit is the preferred food for adults.