My 3 Month Old Keeps Biting His Lower Lip – What Should I Do?

It’s amazing to witness every single milestone in a baby’s life. Little things like when they first smile back at you, wrap their little fingers on yours, or giggle in delight. But sometimes, we would also notice changes that sent us into worry. Such as when you see your baby is biting on his lower lip. The behavior is cute until you notice his lips are almost chapped and bruised.

Like us adults, babies are amazed at discovering new things about their bodies. As their sensory development progresses, they are likely to experiment on how things feel. So, when they start to learn about their lips and tongue’s movement, expect their fascination in chewing or sucking. Babies may also express their hunger or stress by biting their bottom lip. Sometimes they would also chew on their knuckles. More often, teething also prompts babies to develop this behavior. But, is there a cause of worry? How would you stop your little one from it?

Reasons for babies’ lower lip biting

A few years ago, a close friend asked me this exact same question. Why is her baby biting her lower lip? It came to a point where her four-month-old baby developed chapping around her mouth because of it. We deduced it was a simple behavioral change as she is also cranky and exhibits frantic gestures. We did not have an answer for this at that time until we pieced the pieces together.

My friend was going through emotional turmoil at the moment, a rocky path in her marriage. To say that she was upset and stressed is an understatement. As it turned out, the distress did not only affect herself and her breastmilk production. It also takes a toll on her baby that fuels the strange behavior.

Breastfeeding while stressing out (over something like marital issues) can even transfer to your baby via breastmilk.

Yes, stress is also a thing even in infants. And they can absolutely sense it around their surroundings. Unable to express their feelings, you will notice subtle changes in their behaviors and body expressions. When they are anxious over something, they tend to resort to biting or fussing.

But here are other reasons why babies seem to acquire the not-so-cute lip biting habit.

Your baby is teething

A 3 month baby who is teething will likely also bite his lip to relieve his itchy gums and tooth eruption.

Your baby’s itching gums on the onset of tooth eruption will trigger them to suck on their lower lip. In fact, they would gnaw on everything they can lay their hands on to soothe themselves. It mostly happens to babies at their teething age of six months to twelve months. But some children may experience it as early as three or four-months-old. Other teething signs include drooling, hair or ear pulling, and much fussing.

What can you do?

Giving your baby a teether may ease your baby’s teething pain and stop him from biting his lip. Massaging your baby’s gums with a clean washcloth is also beneficial for easing his pain.

However, you may want to think twice about putting your finger inside your baby’s mouth when the incisors are already present. I won’t, for the life of me. You can always go back to giving a teether as an effective solution. Check out how to give a teether properly to your child in this post.

Your baby is hungry

A hungry 3-month infant who is crying and biting his lip at the same time.

Before they get vocal about their feelings, infants communicate what they feel through helpful signals. For your newborn, the very first thing that they will communicate is their feeling of hunger. Crying is mostly a late sign of hunger that you can prevent if you respond to his need earlier. He will either pucker his lips or put his fist on his mouth to let you know it’s feeding time.

Even if he starts on solid food, the cue barely changes. If your baby wants to taste your food, he will likely bite his lower lip to tell you about it. A lot of cute babbling will often accompany this gesture.

What can you do?

When your baby manifests lip-biting during feeding time, respond to his cues immediately. Satisfying your baby’s craving will stop this behavior. Eventually, when they can communicate hunger, the action will just stop.

And if you can teach him some baby sign language, he will mimic the action instead of sucking his lips.

Your baby is self-soothing

3-month baby is self-soothing and biting his lip consequently.

Babies manifest different ways of calming themselves down. Some of them may cry themselves to sleep, while others will go as far as hitting themselves in the head. Self-soothing is an early way of babies learning self-control.

They will often find new ways to relax, and it does include lip-sucking. Self-soothing usually begins at three to four months of your baby’s age. It is common when your baby is about to sleep or in pain, like teething.

What can you do?

There’s little you can do to stop babies from this habit. Self-soothing is a life skill and another strange milestone in the baby’s life. Give your baby a little bit of time to discover ways of relaxing himself.

He knows what to do, and if biting hurts him, he will likely stop the gesture. Some parents may offer a pacifier to help their kids in their wake-to-sleep transition. He will outgrow the habit no sooner.

Your baby has developed sensory motors

Babies are born with reflexes that generally fade at around six weeks of age. By this time, his strength and coordination have improved. He will no longer react mostly on reflexes as he gains control of his senses.

Along with learning new things, babies are also eager to explore the extent of what their bodies can do. They are amazed by movements and are likely to chew or suck when they learn of their oral sensory skill.

What can you do?

The oral mouthing phase is another critical milestone that your child will outgrow. But there are plenty of ways to redirect this mouthing behavior. You can give your little one some sensory development toys to ward off his habit.

For example, a strong teether, pacifier, or dummy will be very useful. Older babies can also have chewy and crunchy food to address their lip-biting habits.

Your baby is stressed out

A stressful environment (or a stressful parent) is enough to send infants into anxiety. These little creatures are absorbent of the emotions around them.

You’ll notice stress in babies when they get fussier than usual, bite their lips or change their sleeping habits. He may also exhibit frantic body movements or change his eating habit.

What can you do?

Stress is a very critical condition that you wouldn’t want your baby to feel. It will have a long-lasting effect on his personality. The best thing you can do is remove your baby from the stressful environment.

Surround him with happy people in a happy home. Hold your baby, do some baby massage and give him reassuring touches. Your little one needs it as much as you do.

When to worry about baby’s lip biting

When to worry about baby’s lip biting

Lip biting is a habit that is comforting for infants and children. But eventually, they will learn to outgrow it as they discover more things about themselves. As parents, you need to help them get through it as much.

If your baby does not let go of it, he has chances of developing an overbite in the long run. Overbite is oral damage that will affect the child’s teeth position. As a result, he will have difficulty chewing. Older children who kept the habit may also have speech difficulty. It happens if they talk around their lips when they are unable to let go of sucking.

So, if your baby refuses to give up the habit past their developmental milestone, touch base with your pediatrician. He will rule out any underlying cause if it is not due to natural responses. Otherwise, you need to stop worrying and let babies handle the changes with minimal intervention.


At what age should the baby let go of lip-biting?

Generally, they will cease with the habit at 12 months of age. It is the ideal time that it stops to prevent oral damages since he likely develops his full set of teeth by this time.

How will I help my baby get through a stressful situation?

The good thing about babies is they don’t hold on to emotions. Keeping him distracted with a happy activity will help ease his anxiety. Touch of reassurances or playing with toys are excellent distractions.

What if the habit does not go away by itself?

Older children will understand if you try to explain the consequence through gentle reminders. You can offer distractions to babies during their idle times, like giving them sensory development toys. It will expand their discoveries and perk their interest in the world around them.


Lip-biting is a developmental milestone in a baby’s life that is not very mainstream to parents. It happens as their natural response to hunger, teething pain, or anxiety. Habits like this will go away as babies begin to explore and discover more things and responses around themselves.

The behavior is nothing parents should worry about. Not unless it doesn’t stop, and he lives with it for an unusually long term. Parents have different ways of helping their babies manage this phase. If you have anything worth sharing, you can share it with our moms around the world. Share your comments in the space below.

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Ann Marie is a licensed nurse in the Philippines. She experienced handling and assisting deliveries of newborns into the world. She also trained in labor rooms and pediatric wards while in nursing school - helping soon-to-be mothers and little kids in the process. Though not a mother by nature but a mother by heart, Ann Marie loves to take care of her younger cousins as well as nephews and nieces during her free time.

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