I have a golden retriever who used to do that when she was younger, and I have had 2 other dogs before. Usually they just mature as they get older. But a suggestion for now would be to use a stern voice when punishing it. Have your kids spend time so that it learns that these people are family and it has to good to them. When it steals food take two fingers and hit it not lightly or really hard on the snout. That doesn't hurt them but it gives them a wakeup call. Hope this helps.