how do i breed watersnails ?

Question
i have a fish tank with frogs,newts and snails. now the snails lay eggs left and right but they happened to be my frogs favorite food !! what i did is that when i saw one of the snails laying eggs i quickly picked them up and put them in a plastic cup with water from the tank. its been about a month now and i dont see the eggs growing or anything. is there a possibility they wont hatch ? and why ?......            
i appreciate your time and i'll be waiting for your answer !             thank you !

Answer
Hi Alex,
Thanks for your question. The eggs probably died because the water became stagnant. You might want to just let nature take its course. If the frogs eat the snail eggs, so be it. Most people cannot stop snails from reproducing and taking over the tank. You have found a way to keep them under control. One thing you might try is to partition a little area of the tank with a net or divider to allow the snail eggs to hatch in the healthy, living water of the tank.
I'm also concerned that you do not over feed. Also, please consider using the product "Cycle" (friendly bacteria) to promote a healthy tank.
My instructions for holistic tank care are posted here:
http://steamboats.com/aquarium.html
Nori