Why do some insects, like butterflies and moths seem to fly so erratically?

Answer 1

My daughter called them flutterbys (((smile)))

Makes it harder for birds and bats to catch them

Answer 2

The familiar, random-looking fluttering of butterflies is really due to the animals using a wide variety of aerodynamic mechanisms as they take off, maneuver, maintain steady flight, and land, said Srygley.
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Free-flying butterflies "use all of the known mechanisms to enhance lift -- wake capture, leading-edge vortex, clap and fling, and active and inactive upstrokes -- as well as two mechanisms that had not been postulated, the leading-edge vortex during the upstrokes and the double leading-edge vortex," said Srygley.

The research showed that butterflies create vortices and double vortices above the leading edges of their wings by varying the twist and speed of their strokes to make sudden changes in pitch.

They use vortices shed from the wing's trailing edge -- the wake -- recycling their own energy to further increase lift. They also use a clap-and-fling mechanism to produce opposite vortices on each wing, which also contributes lift. The red admirals do this by touching their wings briefly, then rapidly separating them. And they use a mix of active upstrokes, which generate lift, and inactive upstrokes, which do not.

The basic butterfly stroke is not smooth. Going into a downstroke each wing is up and back, with the wings' leading edges pointing foreword. As the wings go down and foreword they also continuously rotate, changing the wing angle. Just before the upstroke the butterfly quickly wists its wings so the leading edge points backwards. On the upstroke the wings go up and back and again continuously rotate; there's another quick rotation at the end of the upstroke to position the wings before the next downstroke.

The brief stops before each downstroke and upstroke, and accelerations and decelerations between strokes vary the airflow considerably.

The researchers' smoke patterns showed that butterflies often used different aerodynamic mechanisms in successive strokes.

The familiar, random-looking fluttering of butterflies is really due to the animals using a wide variety of aerodynamic mechanisms as they take off, maneuver, maintain steady flight, and land, said Srygley.

In general, the butterflies made more use of vortices during acceleration, Srygley said. "The leading-edge vortex is most pronounced when the red admiral butterflies are accelerating; when maintaining a steady speed [it] became less pronounced," he said.

http://www.trnmag.com/Stories/2003/021203/Butterflies_offer_lessons_for_robots_021203.html

Answer 3

one day I was out in back of my work (break-time) and i saw this butterfly fly into a small bush and dodge and weave around in there most perfectly. It was then that a realized that they are not on the edge of control - fluttering maniacally - they are the best at doing what they do.
The next day I was walking and this butterfly flew past me and flew straight into the side of a building!!! (So goes my theory on butterfly agility)

Answer 4

You are probably comparing them to birds. If you watched geese fly, you'll probably notice large wingspans and slight wave motions. Insects are more like hummingbirds with smaller wingspans and wings that beat constantly, this therefore causes them to fly in a different pattern.

Answer 5

They must be blinded by some bright light. If there is no light, how can you see them?

Answer 6

They seem to, but they are not. They know what they are doing and where they are going.

Answer 7

It must be due to little bodies and huge wings.

Answer 8

It's probably because it makes them harder to catch - and thus harder to squish, or eat, or otherwise maim and harm.

Answer 9

They smoked insect crack.

Answer 10

cause your face scares them