Learning to use a straw is a skill that requires patience. To teach it, dip the straw into water, place your thumb over the top to trap the liquid, and then release it into the baby's mouth; repeat this a few times to show them the connection. Once they understand the sucking motion, allow them to practice with an anti-gravity straw bottle throughout the day. Don't worry if it takes several days of demonstration; most babies pick up the reflex quickly with consistent, low-pressure practice.