The Stimulator dry fly is a go-to attractor dry fly, particularly when you're dry fly fishing during a big stone fly hatch or salmon fly hatch. This dry fly sits up high in the water, even in faster water. Its "bugginess" also makes the Stimulator one of the very best dry flies to use as an attractor dry fly pattern "prospecting" for trout when there is no hatch. Also, useful as an “indicator” fly.