I think all bottom feeders eat the eggs. I had ONE snail in my 55 gallon when I set it up this January and it had babies (they can do that without a partner ;o) and then we had about a dozen babies and they all had babies and so on, but the Cory cats keep them in check pretty well. If you have a large tank like 55 gallon then I would suggest at least 6 Cories because they are rather small fish. I have a Bloody Parrot, man do I love that little guy he's the CUTEST, and he charges at the snails. It is sad that he cannot eat them because it looks like he wants to!!!
I can't imagine anyone wanting to breed snails?#**&!!#! Moreover, I can't imagine having a problem with getting them to multiply by the thousands ;o) ;o) ;o)
GOOD LUCK TO YOUR BOYFRIEND!
Silver