Nerite snails don't breed in freshwater. Well, they do lay eggs, but the newly hatched snails need to develop in salt water. I have nerites in all my tanks and the eggs have never even hatched. They come in brown and beige stripes (zebra nerites), orangey red with black markings, and small ones that are black and yellow striped (bumble bee nerites). There are also some salt water nerites, so check which they are before buying.