awww, but aquatic snails are quite cute really!
One of my tanks started off with just one snail that had hitched a ride on a plant (yeah, sometimes washing just doesn't catch them if they are inside the sponge wrap at the bottom...) - very soon I had loads of them, slip sliding all over the gravel and plants. I found them fascinating to watch once I'd gotten over the shock. Eventually they all seemed to disappear as fast as they came! I sometimes spot the odd one here or there but they never did my tank any harm, in fact I think they helped keep it clean.
At least they don't slither all around the house - which is what happened when my daughter secretly decided to keep a box full of garden snails, hidden in the hallway (with NO lid on either!).
Anyway, a tip for future reference when buying plants is to take off the metal clip and sponge and give everything in there a thorough wash to get rid of any baby snails or snail eggs that might be lurking there, and wash the sponge too, or cut your own piece of sponge off if you have a box of the white filter sponges handy.
Athena
The corys didn't seem interested and the last thing I want is ugly slimy snails crawling all over the place 
