Most often you will find the caddis larvae on the bottom and they will only accidently drift down stream in moving water or in search of new feeding grounds. Those living in still water, will only move across the bottom. It is necessery to fish your imitations of the larvae as close to the bottom as possilbe. Many anglers would say that an imitation of a caddis larvae are among the best, if not the best, trout fly around.
Please note the number at the end of the fly name is related to the size of fly and not the amount you will receive.
So for example Mayfly Nymph 3 is only one fly and not x3.