When the word began to get out, the idea of tying imitations of aquatic worms was not met with universal approval in the fly-fishing community. It seems that worms had somehow gotten a bad name. I think a fishing pal of mine hit it on the head when he said, It just pisses them off that you can catch trout, I mean really big trout, on a fly that a five-year old can tie in twenty seconds!
As much as anything, the anglers will clue you in to the midge hatch. You will see them hunched over in concentration like herons. The better ones will be in as close as they can get to the dimpling trout. What you'll notice is the rythmic flicking of casts toward a porpoising trout and the lack of any other motions. The only exception will be the gentle tug that sets a very small hook attached to the leader by a very delicate tippet. The playing of the trout, if it is a good one, will be a cat-and-mouse sort of ecstacy.
A standard saying among fly fishermen is that trout spend anywhere from 80 to 90 percent of their time feeding below the water's surface on the immature forms of aquatic insects. Some anglers are even more precise, but whatever the exact percentage , it's safe to say that to fully appreciate any tailwater fishery you will have to learn the fine art of nymphing.