Nature Spirit dyed Turkey Biot. There is no application to a caddis or mayfly that is more perfect than a turkey biot. The spectacular striated abdomens on DFI's patterns are routinely created with biots. If 99.9% of insects have segmented body, why shouldn't yours? If you need help applying biots, purchase DFI's Colored Emerger DVD (Fly Tying Library) for all you need to know about wrapping a biot.