Snails that won't breed?

Olive Nerite snail eggs will not hatch in freshwater. So you'll just have the hassle of occasionally cleaning up egg cluthces above the waterline.
 
mystery snails are either male or female - they can'e reproduce without a mate, and even if they had a mate and laid eggs, the egg sacs are big orange clusters laid above the waterline. very easy to remove.
 
my only problem is that the ones i have eat my plants. otherwise I love them... my backyard is host to hundreds of yellow snails, they are hard to avoid stepping on after it rains. I've dreamt of setting up a "brooklyn nature" tank with just things found in my yard. it would be a very crowded tank.
 
I think they are related to guppies. Regardless of what they are or are not supposed to do, if you add water....
 
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