If your guest list allows and you want the kids there, invite them. If you don't have room for the kids, leave their names off the invite. I believe most people understand that if their child's name is not on the invite, they aren't invited. You'll probably have people who bring unwanted kids as well but that's something you really can't control.
A lot of people actually might enjoy not bringing the kids because it becomes more of a hassle for them with children.