Adults are most active in the spring, summer and sometimes autumn (if a second generation is born in that year). They are one of the few species that hibernate overwinter. This means they are also some of the earliest butterflies seen in the spring. They prefer sunny areas near running water. Streams, creeks and fountains near open meadows or gardens are good places to find them in flight. They are well-adapted to urban areas as well as wild so they can be seen in parks, backyards and business parks.
The caterpillar feeds on willows. It is almost completely black with several black bristle clusters on its body. Small white and red spots line the body. The caterpillar feeds on the leaves of willow, elm, cottonwood, birch, hackberry and poplar trees.