Babies are never candidates for discipline or physical punishment. They're too little to understand and follow rules. Like adults, children respond better to approval and affection than they do to punishment. Examine your expectations for your kids. There are no perfect children, just as there are no perfect parents.
Parents commonly have expectations for children that are beyond their capabilities at that age.
If your children consistently fail to meet your expectations, the expectations probably need changing, not the children. Shame, rejection, withdrawal of affection, or preferential treatment of one child over another are inappropriate and ineffective ways to discipline. If you need help . . . Asking for help is a sign of strength. We'll put you in touch with someone who can offer support and help.