The painted lady is known for seasonal mass migrations across Europe and Africa.
Vanessa cardui can move between North Africa and Europe in successive generations. Individual butterflies do not normally complete the entire round trip alone; instead, generations develop and continue the movement as conditions and food plants change. Favorable weather can produce enormous influxes into parts of Europe.
Researchers have shown that painted ladies can fly at considerable altitude, using favorable winds to cross large distances. Their migration is flexible rather than a single fixed route. Numbers vary greatly from year to year because rainfall, plant growth, wind, and temperature affect breeding success.
This species is sometimes overshadowed by the monarch, whose North American migration is more widely publicized. Painted lady movement is nevertheless one of the most extensive migrations known among insects. The same butterfly may be called the cosmopolitan or thistle butterfly in some languages and older sources.