Anenteome Helena - Assassin snails - will pick up scraps, not over populate or lay nasty looking eggs and rid you nuisance snails
Nerita sp. - Nerite snails - will graze algae and some of the "fuzz", lays hard shelled eggs at random but does not hatch in fw.
These two are a killer combo
If they do I haven't noticed... the trap door of the nerites work pretty well and I've never witnessed or noticed any losses. I use both together in my tanks.
, onto oncoming snails and devour them through that way and do not bother with those with a strong operculum.I don't think they have the means to pierce through the shells, from what I have witnessed in my tanks and from what I gather from any information online is that the assassins will "pounce", for the lack of a better term, onto oncoming snails and devour them through that way and do not bother with those with a strong operculum.
This is what I have witnessed in not only my own tank but several fellow hobbyist as well. The "piercing" method you speak of is very interesting though and I would love to see pictures of the aftermath!