Winter Feeding Fish

[njnympher]

I've been Fly Fishing for close to 2 years but have never fished the Winter and until now!From what i heard and read,i knew Insect Activity would be at hault with the exception of Midges coming off but as for Mayfly i could forget it!Well since fishing and braving the cold along with others i have come upon a question that i can't answer but hope all here might be able to provide thoughts and opinions to my question.Since i've started fishing i've been a match the hatch guy and try to do it with patterns i tie.Now well on stream i pick up rocks and see no Insects there for i've stuck to Midge patterns so far with good results.Now i often will tie on a 20-22 Hares Ear and to my suprize.I catch fish even though i seen no Mayfly Nymphs in the water.Now what do you guys think it maybe that provokes a Trout to take a 20 Mayfly Nymph when there much smaller in there in the water,like a size 50 to the point you can see them.