Today I got hold of some Assassin snails. I've been reading quite some time about them & this is some of the information I've got from the internet......
The name says it all.... Assassin snails seek out other snails & eat them. These snails are said to be great in "pest" snails infested tanks but I'm not sure if they're capable of eating any type or size of snails. They grow to 2.5cm in length & they move around the tank with their proboscus extended.
These snails are freshwater snails & tolerate a wide range of water conditions. As with all snails, they don't tolerate ammonia & nitrite. The pH should be over 7 & this way it will prevent their shells from eroding.
Assassin snails will attack & eat many different species of small snails, but they seem to prefer the ramshorns. Through relish live snails, they will also accept sinking pellet foods. (corydoras beware)
Assassin snails will not breed much in aquariums & only lays one egg every month or so. These eggs are adhered to rocks & are often eaten by other tank mates.
These Assassin snails are said to be very effective of ridding your tank of "pest" snails without the use of chemicals, battery or the lettuce method & are much more natural approach to pest population control. They are also very beautiful & have their shell banded with yellow & black stripes.
Anybody keep these snails & if yes, are they safe with fry?. Any information is greatly appreciated & thanks in advance.
I'll post some pictures, as soon as I'll be able to "focus" them. 
Please treat Corydoras as community inhabitants & not as scavengers.
