Many of us come from a trout fishing background as well as are relied on to fish behaving in a rather foreseeable means. If there is a caddis hatch taking place and you could physically see trout proactively feeding for caddis there is a great chance that if you make use of a pattern mimicing a caddis you're visiting apprehend a trout. There is a direct as well as apparent relationship between exactly what fish are eating and exactly what will certainly provide you the very best possibility for success.
The various other popular view on the matter is that they take based upon aggressiveness. When they see a small fish in their location they obtain perturbed and they pursue it. With swing flies the fly will look like its running away the location as a result of the visibility of a bigger predator which's when the steelhead strikes. This is the idea behind Spey fishing.