The Dawns

Then, what should I be feeding my snails specifically?

All that I have read and all that I have been told by other people (experts?); is that snails will not eat my live, healthy plants. They will only eat the dead plants, leftover food, and the such. I have trumpet snails and Ramshorn snails in this tank. Why do I keep finding them on mine healthy, live plants? Was I misinformed? I use aquarium co-ops easy green and a biological substrate specifically for plants.