In article ,
says...

For a small skittering type caddis with a front hackle, I like stacked
guard hairs from mink tails. I tie them long so they extend the same
amount as a conventional tail. They're very stiff and light and result
in a very animated fly. (not my pattern but I don't remember where I got it)


It sounds like Leonard Wright's Fluttering Caddis fly, from back in the
70's. I tie something similar too.

I like mink tails a lot. They are perfect for tailing mayfly patterns:
stiffer than hackle fibers, but finer than deer hair or bucktail.

Kevin