Baby Snails?

I bought 3 snails yesturday and it came with two baby ones. I separated the snails. The three others are in a tank of there own with four fish (Black moor, and three goldfishes) Well anyway this strange brown stuff came out of two of the snails??? Im guessing they are baby snails. Too tiny to make a guess. Because it's sticking to the snails Im guessing that it is something important. Am I right. Im not sure what the breed of the snails are, I got them at petsmart.