The caddis fly is a staple on trout streams. it's sort of like bread and butter at the dinner table. The caddis can be fished in many ways from the nymph to the emerger to the adult. In any one form it can be deadly. Here are a couple of versions of the caddis that I like to fish. It's more like one version which is the emerger but fished at different depths in the water. The first fly is tied with a body of hares mask. The hackle used is a a dry fly rooster. What I use is these India rooster capes. These birds are smaller than domestic capes and the hackle is semi stiff.
The first fly is what I call the "Hard Caddis" it is tied with the rooster cape and is fished just below the surface. Technically it's still a wet fly but the dry fly hackles causes it to do some different things in the water. It will break the surface and appear to be a struggling adult. Very effective.
This is a partridge feather. It is taken from the back of the bird and offers a brown color. It is tied on the fly the same as the rooster hackle. Being a much softer hackle the fly works in slightly deeper water. It's pulsating hackles will draw strikes.
The "Soft Caddis"
By the way the feathers on those India rooster capes make great wings for small streamer flies.