Even if you don't know much about insects, you've probably been taught the difference between a butterfly and a moth. Butterflies are ornate, colourful and active during the day, while moths are... ornate, colourful and active during the day?
The Uraniidae are a family of about 700 species of mostly pantropical moth. The family is united primarily by their distinctive sexually dimorphic tympanal organs: in females, the tympanal organs open ventrally on the first abdominal sternite (as in a number of other moths), but in males they open dorsally or laterally at the junction of the second and third segments (Scoble 1995). About 600 of the 700 species of uraniid are assigned to the subfamily Epipleminae, and are generally nocturnal, brown and cryptic. Many epiplemines roll their wings up when at rest, so that they resemble a small brown stick.
However, some members of the subfamily Uraniinae have become diurnal. These diurnal species have brightly iridescent wings with prominent tails, and have often been compared to swallowtail butterflies. One of the best-known species is Urania fulgens, a South American species that migrates north into Central America at certain times of year. Migrating individuals may reach as far north as the southern United States.
Scoble, M. J. 1995. The Lepidoptera: Form, function and diversity. Oxford University Press.