Why Do Babies Stick Their Tongues Out? A Parent's Complete Guide

It’s one of the most endearing—and sometimes puzzling—behaviors of a newborn: the tiny tongue that seems to have a mind of its own, poking out to greet the world. As a parent, you might wonder if this constant tongue action is normal or if it means something specific.

The reassuring answer is that in the vast majority of cases, an infant sticking their tongue out is a perfectly normal, healthy part of their development. This simple gesture is a complex tool for communication, exploration, and survival. However, understanding the different reasons behind it can help you tune into your baby's needs and know when it might be worth a chat with your pediatrician.

Common and Normal Reasons Your Baby Sticks Their Tongue Out

From innate reflexes to their first attempts at social interaction, your baby’s tongue is hard at work. Here are the most common reasons for this behavior.

Innate Reflexes: The Tongue-Thrust (Extrusion) Reflex

Babies are born with several primitive reflexes, and the tongue-thrust reflex is one of the most important. When something touches your baby's lips, their tongue automatically pushes forward.

• Purpose: This reflex serves two key functions. First, it helps them latch onto a breast or bottle for feeding. Second, it's a protective mechanism that prevents them from choking on foreign objects or food before they're ready for solids.
• Timeline: This involuntary reflex is strongest in the first few months and typically fades between 4 and 6 months of age—right around the time they are developmentally ready to start trying puréed foods. The disappearance of this reflex is a key sign that they can manage solids.

A happy baby sticks their tongue out while lying on a soft blanket.

Communication Cues

Long before they can say a word, babies use their bodies to communicate their needs. Sticking out their tongue is a surprisingly versatile signal.

"I'm Hungry!"

Sticking their tongue out is often an early hunger cue. You may notice it alongside other signs, such as:

• Rooting (turning their head to search for the nipple)
• Smacking or licking their lips
• Putting their hands to their mouth
• Making sucking motions

Crying is actually a late sign of hunger, so catching these earlier tongue cues can help make feeding time smoother.

"I'm Full!" or "No, Thanks!"

The same action can mean the complete opposite. A baby who is full may stick their tongue out to block the nipple or spoon. When starting solids, they might also do this to show they dislike a new taste or texture.

A Tool for Exploration and Development

Your baby is a tiny scientist, and their mouth is a primary tool for learning about the world.

• Sensory Discovery: The tongue is full of sensory receptors. By sticking it out, babies can explore different textures and sensations, from the fabric of their onesie to the feel of their own skin.
• Developing Motor Skills: Sticking the tongue out helps babies gain control over their facial and mouth muscles. This is crucial practice for developing the coordination needed for eating solids and, eventually, for speech.

Early Social Interactions

Your baby is wired to connect with you from day one, and they are surprisingly keen observers.

• Imitation and Play: There has been a long-standing scientific discussion about newborn imitation. While some studies suggest babies as young as a few weeks old can mimic facial expressions like sticking out a tongue, newer research proposes it might be a sign of excitement or arousal rather than true imitation. Regardless, as they get older, they will certainly imitate you playfully to engage and get a reaction.
• Getting a Reaction: Babies quickly learn about cause and effect. If sticking their tongue out makes you smile or laugh, they're likely to do it again to get that same loving response.

A Tale of Two States: Tongue Out While Awake vs. Asleep

The context of tongue protrusion can offer clues to its meaning.

While Awake

During waking hours, tongue movement is usually an active, intentional behavior. It's tied to the reasons above: feeding cues, exploration, communication, imitation, and play. It can also be a way for them to soothe sore gums during teething or a sign of passing gas.

While Asleep

When your baby is sleeping, seeing their tongue out is more likely related to involuntary actions or their state of relaxation.

• Reflexes: The tongue-thrust reflex can still occur during sleep.
• Mouth Breathing: If your baby has a stuffy nose from a cold or allergies, they may breathe through their mouth, causing their tongue to loll out.
• Relaxation: Deeply relaxed muscles, including the jaw and tongue, can lead to the tongue sticking out during sleep.

When to Consult a Doctor: The Diagnostic Threshold

While almost always normal, persistent tongue protrusion can occasionally be a sign of an underlying medical condition. It's important to look at the behavior in the context of your baby's overall health and development.

Potential Medical Reasons for Tongue Protrusion

If your baby's tongue seems to always be sticking out and they have trouble keeping it in their mouth, it may be linked to one of these less common conditions:

• Macroglossia (Enlarged Tongue): The tongue is physically larger than average, making it difficult to fit in the mouth. This can be an isolated trait or part of a genetic syndrome like Beckwith-Wiedemann syndrome or Down syndrome.
• Micrognathia (Small Jaw): An unusually small or recessed jaw may not provide enough space for the tongue, causing it to protrude.
• Hypotonia (Low Muscle Tone): Conditions that cause weak muscle tone, such as Down syndrome, cerebral palsy, or DiGeorge syndrome, can affect the muscles that control the tongue and mouth.
• Ankyloglossia (Tongue-Tie): The strip of skin under the tongue (lingual frenulum) is too short, restricting the tongue's range of motion and sometimes causing it to stick out.
• Breathing Obstructions: Enlarged tonsils or adenoids can block nasal passages, forcing the baby to breathe through their mouth.
• Oral Masses: In very rare cases, a cyst or other growth in the mouth can push the tongue forward.

Red Flag Symptoms: When to Seek Medical Advice

Trust your parental instincts. If this behavior is accompanied by other concerning signs, it's always best to consult a pediatrician. Schedule an appointment if you notice:

• Difficulty feeding, such as trouble latching, sucking, or swallowing.
• Excessive drooling beyond what's normal for teething.
• Trouble closing their mouth or if the tongue seems to always hang out.
• Noisy breathing, wheezing, or other signs of respiratory difficulty.
• The tongue appears disproportionately large for their mouth.
• The tongue-thrust reflex persists strongly beyond 6-7 months of age.

A Fascinating Connection: Concentration and the Tongue

Have you ever noticed a child—or even an adult—sticking their tongue out while focusing on a delicate task, like threading a needle or drawing a careful line? This isn't just a cute quirk; it has a neurological basis.

The brain regions that control fine motor skills for the hands are located very close to the regions that control the mouth and tongue. Neuroscientists believe in a concept called "motor overflow," where intense neural activity in one area spills over into the neighboring region. As your baby concentrates on a fine motor task, like trying to grasp a toy, the intense brain activity can overflow and cause their tongue to move, too.

The Bottom Line

Watching your baby stick their tongue out is a delightful part of their early journey. It's their first word in a long conversation, a tool for discovery, and a sign of their developing brain and body. By understanding the many normal reasons behind it, you can better appreciate these charming moments while remaining confidently aware of the few signs that might warrant a call to your doctor.

References

• Medical News Today. (2020). Baby sticking tongue out: Causes and what to do. https://www.medicalnewstoday.com/articles/baby-sticking-tongue-out
• Healthline. (2018). Is My Baby Sticking His Tongue Out Normal? https://www.healthline.com/health/baby-sticking-tongue-out
• Centers for Disease Control and Prevention (CDC). Signs Your Child Is Hungry or Full. https://www.cdc.gov/nutrition/infantandtoddlernutrition/mealtime/signs-your-child-is-hungry-or-full.html
• Oostenbroek, J., Suddendorf, T., Nielsen, M., et al. (2016). Comprehensive Longitudinal Studies of Newborn Imitation: A Review and Meta-Analysis. Current Biology, 26(10), 1325-1328. https://www.cell.com/current-biology/abstract/S0960-9822(16)30257-330257-3)
• Live Science. (2021). Why do we stick out our tongues when we're concentrating? https://www.livescience.com/why-stick-out-tongues-concentration