Fluttering

Have you ever watched a butterfly in flight and tried to figure out where it will go next? The butterfly will soar three feet in the air, veer left, drop, veer right. It will look as if it’s heading for a flower, then land on a rock.
Of course, it is biologically programmed to do that. It makes it hard for a predator to catch the butterfly when the predator can’t figure out where it is going.