I was at Petsmart the other day and was looking at their tanks. Well I spotted these little snails all over some of there tanks and upon closer inspection they looked identicial to the pictures of nerite snails I have seen. They are fairly small about between the size of my ring fingernail and my pinky fingernail, maybe smaller than that. They didn't seem like they were selling them though, I thought of just asking for a couple but I don't want to buy them and then have an infestation of snails if they weren't nerite snails. What do you guys think?