Tongue protrusion, or licking, is a common, typically normal, and harmless behavior in infants, especially during the first six months of life. This reflexive action is part of a complex set of behaviors that help newborns navigate the world and communicate their needs. The reasons for this consistent tongue movement range from instinctual biological reflexes to early sensory exploration and motor skill development.
Signaling Hunger and Feeding Readiness
The most frequent reason a baby extends their tongue is linked directly to feeding and survival. Newborns possess the tongue thrust reflex, also called the extrusion reflex, which causes the tongue to push outward when the lips are touched. This reflex is protective, preventing the baby from choking on foreign objects, and simultaneously aids in latching for nursing or bottle feeding.
Tongue protrusion is also an early, subtle cue that signals hunger, often preceding crying. Before a baby cries, they may lick their lips, open their mouth, or make small smacking sounds. These actions are part of the rooting reflex, where the baby turns their head toward a touch on the cheek or mouth, extending their tongue in search of a food source.
The tongue thrust reflex remains present until around four to six months of age. Its eventual disappearance is a sign the baby is ready to begin solid foods. Any new food or item introduced before this time will likely be pushed out of the mouth by the tongue, acting as a natural defense mechanism.
Sensory Exploration and Motor Development
Beyond basic feeding, the tongue serves as a primary tool for sensory exploration and developing oral motor skills. Infants learn about their environment by bringing objects to their mouth, and the tongue is the first way they experience textures. This oral exploration helps the baby build a mental map of their mouth, which is crucial for future speech and eating skills.
As the baby grows, they gain voluntary control over the muscles in their mouth and tongue. Sticking the tongue out becomes practice, refining the coordination needed for advanced movements like lateral tongue movements required for chewing and managing solid foods. This practice is a developmental milestone, shifting from reflexive action to intentional movement.
The behavior can also be a form of early social communication and imitation. Infants can mimic facial expressions, including sticking out their tongue, when interacting with a caregiver. This interaction is a foundation for social learning and connection.
Potential Medical Causes and When to Seek Advice
While tongue protrusion is nearly always a normal developmental behavior, in rare circumstances, it can signal an underlying issue. If the tongue consistently hangs out of the mouth, or if the protrusion persists past six months, discussion with a healthcare provider is warranted. Conditions causing macroglossia (an unusually large tongue) can result in the tongue not fitting comfortably within the oral cavity.
Other potential medical factors include low muscle tone, which affects the tongue and surrounding muscles, or chronic nasal congestion. If a baby cannot breathe easily through the nose due to enlarged tonsils or adenoids, they may breathe through their mouth, causing the tongue to rest forward.
Parents should seek medical advice if the protrusion is accompanied by other concerning symptoms:
- Difficulty feeding
- Excessive drooling unrelated to teething
- Difficulty swallowing
- Poor weight gain