I have five pond snails. I have two very tiny babies, two medium, and one very large one. I got them from science class. They are living with four guppys. I have a question. The big snail keeps on tugging at the smaller snails shells. I don't know why this is happening, or how to stop it. Please write back. Also, I was wondering if it is actually okay to feed them guppy food. thanks SUPERMAN