Will my ramshorn snails be ok?

I have 10 itty bitty ramshorn snails like the size of a letter on a quarter! Yeah, they're that small! Well, I'm keeping them in a really small bowl like half the size of a mug. Will they be ok if I keep them in there, or do I need to transfer them to a real tank? Also,could you tell me everything else there is to know about ramshorn snails? Thank you!