The first thing an angler should do is to try and eliminate the offensive odors that could be transferred to the fly. Plant extracts are very effective in covering human odors. Before using the fly, first rub it onto some debris at streamside or you can find some aquatic plant and rub the fly against it or you can simply rub the fly into some soft mud then rinse it in the water before use. I don't want to make a real big deal out of this; however, I do want you to have all the facts before venturing out. By doing this you will be providing an odor that the fish is not accustomed to smelling, yet is not offensive to the fish.
Oh yes, I can hear a hundred anglers thinking to themselves that they have never had a problem and just maybe Babine's making a mountain out of a mole hill. Guess what? I think your right, I just want to give you all the information on the subject to process as you like.
The fish will use it's senses in the following order: First, the fish will feel the presence by sensing the sound wave vibrations of the intruder. This alerts the fish that something is heading its' way and it may be edible. The second thing the fish will do is wait for a second opinion from either its' smell or sight capabilities before it will commit towards any type of action. All fish will not take any action unless they can determine the presence of the intruder with at least two of its' senses.
In northern New England, most early Mayfly hatches begin well before the fish are in the mood for surface feeding because the predominant insect activity is below surface. Temperatures are still cold and the spring foliage has yet had a chance to provide a protective canopy over the still cold rivers and streams. Below the waters' surface, at any given time, the predominant aquatic insect activity surrounds the species of insect that is next to emerge into the air-breathing world above. Once the water temperature attains 50 degrees for three consecutive days, insect emergence will start to take place. Along with Chironomid (Midge) activity and some early stonefly hatches, the small swimming Blue Winged Olive (BWO) nymphs will be among the first mayflies followed quickly by the Grey Quills. The clinging Quill Gordon's and the March Browns are among the first clinging nymphs to join the world of the air-breathing insects. As the water temperature rises, so do the larger March Browns, Black Stoneflies and the start of many Caddisfly species.
The fish's rule is this, if it looks right, sounds right and acts right, then it darn well might taste right! This rule allows us, the anglers, to have the advantage. This is why a fish will attempt to consume an object made from items such as: animal hair or fur, bird feathers, thin ribbons of metal and all the other synthetic materials that all our offerings are constructed based on Size, Color, Shape and Action. The only time that the fish realizes that the offering is not to its' liking is when the offering is in the fish's mouth and then it's too late and that's a good thing.
Where a fish will feed will always be determined by its' environment. The "Golden Rule" of a fish's survival is that it will never expend more energy to obtain its' food then the energy received by obtaining it. Remember that fish will always react to their senses and don't think. For that reason, they will always seek cooler water when the temperature becomes uncomfortable and the opposite will take place when the water temperature is too cold. The fish will position themselves within the water column looking for a location that will provide comfort, shelter, a consistent food source, and protection from predators. The comfort lie will provide protection from forceful currents and the area that provides protection, will have an easily reached area to retreat to when alerted to any possible danger. This area will be located in a spot that will protect the fish from aerial predators. The best lies are the ones that provide more than one of the fish's needs. These lies will also contain the larger fish.
Depending on the fish's needs, these lies are in various locations within the water column. There are Feeding Lies, Prime Lies and Protective Lies. Fish will also cruise the shallows at various times to take full opportunities provided by the actions of Aquatic Insects.
During the early spring, when the water temperature is below 50 degrees, the fish will feed exclusively along the bottom and in areas that will provide them with small bait fish, fresh water shrimp, amphibians, crustaceans, shellfish, worms, larvae, Pupae and other nymphal life forms. It is said that a fish will obtain more than 80% of its total diet from the bottom of the water column. The fish will even cruise along the shallow areas called flats.
Not only does the fish find warmer water, but also these areas are usually muddy or silt covered and great areas for aquatic insects. As the water temperature changes and both the surface and sub-surface insect activity begin, the fish will change its feeding habits. Now that the water temperature reaches an uncomfortable range for the fish, it will once again retreat to the cooler waters of pools, faster moving waters of the riffles or in the areas where feeder brooks or other waters enter the fish's body of water. In short, if the fish will adapt to its environment, so must the angler adapt in order to find the fish.