This is the first time that anyone has captured images that show what the wing beats of free-flying insects do to the air they flutter on. (Other visual studies have used tethered insects, moths, for example, glued to a lightweight rod.) The red admiral butterflies, moving without restraint, show an extraordinary agility and complexity in their flight. Not only do they use many different wing strokes, they use them on successive wing beats.

"One insect uses all the known aerodynamic methods that anybody has conjectured," said Dr. Adrian L. R. Thomas, an author with Dr. Robert B. Srygley, now a visiting researcher at the Smithsonian Tropical Research Institute in Panama, of a report published today in the journal Nature. "That's a big surprise."