Scientists in Japan have been studying the way butterflies fly. They have built a mechanical replica of a swallowtail butterfly.
Among the various types of butterflies, swallowtails are unique in that their wing area is very large relative to their body mass. This combined with their overlapping fore wings means that their flapping frequency is comparatively low and their general wing motion severely restricted.
As a result, swallowtails' ability to actively control the aerodynamic force of their wings is limited and their body motion is a passive reaction to the simple flapping motion, and not -- as common in other types of butterfly -- an active reaction to aerodynamics. ( Science Daily )
Below is a short movie of this artificial swallowtail butterfly in flight. The replica model is properly called an ornithopter. The study of aerodynamics is a relatively young one, and there are still great discoveries waiting to be made.