Diving, sinking or tumbling, I am not sure a fish will ever extract the niceties of the barbules of a pheasant tail feather barb. Many synthetics, today, grab the movement or flash that suggest movement/life for an offered replica. But, for a natural material that has just the right color, edginess and durability, Pheasant Tail barbs are a wonder material.

Pheasant Tail Antenna/Wing on BH Caddis Pupa (SwittersB)