Yep, they came in a canister with granules and "crisps" of food. You can choose between the three which to feed. The baby shrimp do look pretty big for the betta's mouth, so I will be sure to cut it up. As for the Nerite, they only reproduce in brackish water, so no need to worry about an overpopulation of snails! They are master algae eaters, and grow to be pretty small. They also will not eat live plants. :)
I have to agrees on nerites; they're a good bit better than pond snails in tanks--though if you have enough fish, they'll eat the baby pond snails for you (we only have about 10 of them that we've found in our pond. The other fish eat the babies, lol.).
If I ever find the big old pond snail we have again, I should take a picture of it, as reference when people ask if what they have is one. xD