Think of them as a bunch of free janitors... running around and cleaning your tank for free!! Most snails won't disturb live plants (although they'll eat dead parts off... sweet!) and I've never had snails do anything but consume fish that were already dead. (in fact, once in a while, when a mollie died, i'd just leave it in there... it would be completely consumed in a day or two).
You can develop A LOT of these little guys in a short while... squishing them is kind of gross. YoYo loaches clean up on them in no time flat. Scooping out a spoonful of them and tossing them into other tanks for fish to eat is another way to "recycle"
It has been suggested that placing a jelly jar with some sort of "bait" in the bottom (algae wafers, perhaps??) and removing the jar/bait/snail combo the next morning might thin the herd.
Generally, they don't do any harm (depending on the type, you'll have to watch them for injury to plants, although i've never had this problem) and a whole lot of good!
You can develop A LOT of these little guys in a short while... squishing them is kind of gross. YoYo loaches clean up on them in no time flat. Scooping out a spoonful of them and tossing them into other tanks for fish to eat is another way to "recycle"
Generally, they don't do any harm (depending on the type, you'll have to watch them for injury to plants, although i've never had this problem) and a whole lot of good!

