Something I have been considering for some time is how much “noise” a fly makes. Its not noise we can hear, but fish don’t have ears; they have a lateral line that senses vibration in the water.
We all know that a dragging fly can put fish down. In a situation where drag, or the lack of it, is important could it be the vibration that a dragging fly sets up in the water that puts the fish off? A small may fly drifting on the current doesn’t make any vibration in the water. We present a fly. It drifts nicely then starts to drag. The fish starts to rise, then turns away, and is gone. Think of reaching for a sandwich on your plate. It it suddenly made a noise wouldn’t you pull your hand away?
Conversely there are some insects that make a lot of noise. The first that comes to mind is the caddis fly. Here we sometimes pull the fly across the water to get a take. Not only is this visually attractive it must be setting up vibrations in the water that the fish will be attracted to.
Thinking about this I’ve been changing slightly how I dress some of my flies. Mostly wet flies. Ones which will be pulled. By using dry fly saddle for the palmered hackles the fly will will give the fly more “buzz” than a softer hackle, that will collapse. To keep some of the movement I put a soft hackle at the head.
It isn’t something I have read anywhere and I would be interested in what you all think. Am I barking up the wrong tree?
When you say fish - presume you are talking mainly about trout(We all know that a dragging fly can put fish down. In a situation where drag, or the lack of it, is important could it be the vibration that a dragging fly sets up in the water that puts the fish off? )
The crowd that fish for bass have been tying flies for years that make enough noise (pops and gurgles and rattles) to make any self respecting trout head for the hills.
Do you not think a trout would respond to the noise of a mouse struggling to get across a stream or an injured dragon or damsel fly on the surface of a lake? Trout seem to be a little more shy than a bass but they are still predators and will attack an injured prey. Maybe that’s an area trout fisherman have not pursued adequately.
My thoughts are mixed on your question. I think noise or drag would be something to consider if fishing a pond or lake containing trout because a pond or lake would normally be deeper and have more “color” to the water. In deeper or “colored” water, the noise/drag may be something a person needs in their flies to attract the attention of a trout that is in deeper water or water that is not usually crystal clear. In most quality streams the water is shallow and very clear. An insect floating on the surface will be seen by the trout and it must float identical to the “real” insect. If it starts to “drag”, this is seen by the trout as not being a natural drift that they have seen many times before and this causes them to be wary of what it is or is not. So, I feel that if the real insect usually puts up a lot of noise on the surface, like a grasshopper or cicada, when it lands on the water, this would be seen by the trout as being natural and they would eat it. If the real insect just floats along with no noise or drag, then your imitation needs no noise or drag or it may cause the trout to be wary of it. I have watched trout trying to attack damsel flies as they flitter above the water and there is no noise or drag attracting the trout, but, it is brought to the trout’s attention by being seen from clear shallow water.
So, I feel that if the “food” you are trying to imitate usually makes a lot of noise or trashing on the water, then your fly needs the same noise or thrashing. If the natural does not make noise or drag, then your imitation needs none because it is seen and not heard by the trout. I honestly feel a trout feeds mostly by food that looks alive and not by noise or drag. My definition of “looks alive” would be a fly that has movements of the fly material that would represent the “legs” moving in the water or gills filtering water.
These are just my thoughts on this as far as trout are concerned. Now bass, muskie, pike and other larger species which are use to eating much larger food than insects, my thoughts would be different.