A few years ago, I started using Ostrich Herl for the abdomen of The Orb Emerger (Callibaetis pattern). I also used Ostrich Herl for the tail and as emerging wings. I like the results. I have to believe there is a subtle yet recognizable movement to suggest life in motion. So far, I have only used this pattern on lakes over Chironomid and Callibaetis hatches with some success.

Here, I used a mallard fiber tail and then wrapped up tan and black ostrich herl. I wound a single strand of pearl krystal flash up through the wrapped ostrich herl. Right at the head of the thorax area, I did a sparse dubbing of peacock ice dub.
The same Ostrich Herl components. I just messed with the photo composition a bit for a different effect. That thorax head looks buggy though.