Babies pucker their lips for several reasons, and most of them are completely normal parts of development. Depending on your baby’s age and what’s happening around them, lip puckering can signal hunger, a built-in survival reflex, early social interaction, or simply the way they explore the world. Here’s what’s behind each one.
Feeding Reflexes Present From Birth
Newborns arrive with two powerful reflexes that involve the lips and mouth: the rooting reflex and the sucking reflex. Both are involuntary, controlled by the brainstem, and exist for one purpose: helping your baby find food and eat.
The rooting reflex kicks in when something touches or strokes the corner of a baby’s mouth. In response, the baby turns toward the touch, opens the mouth, and thrusts the tongue outward. It’s the reflex that guides a newborn toward the breast or bottle. The sucking reflex is separate. It activates when something touches the roof of the mouth, triggering the coordinated suck-and-swallow pattern that allows a baby to actually take in milk. This coordination between breathing and swallowing begins developing around 37 weeks of gestation, which is one reason premature babies sometimes struggle with feeding early on.
Both reflexes can produce lip puckering, pursing, and small mouth movements even when a baby isn’t actively feeding. You might notice your newborn making these motions during sleep or when their cheek brushes against a blanket. That’s the rooting reflex firing in response to light touch, not necessarily a sign of hunger.
Hunger Cues That Start at the Lips
Outside of reflexes, lip puckering is one of the earliest signs that a baby is getting hungry. The American Academy of Pediatrics identifies several mouth-related hunger cues that typically appear before a baby starts crying:
- Licking the lips
- Sticking the tongue out
- Rooting, or moving the jaw, mouth, and head as if searching for the breast
- Putting a hand to the mouth repeatedly
- Opening the mouth wide
- Sucking on anything nearby
Crying is actually a late hunger cue. By the time a baby is wailing, they’re often too worked up to latch or settle into feeding easily. Watching for the subtler lip and mouth movements gives you a head start. If your baby is puckering, smacking, or licking their lips and it’s been a couple of hours since the last feeding, hunger is the most likely explanation.
Mimicking Your Face
Babies are wired to study faces from the very beginning, and lip puckering can be an early form of social imitation. Research from the University of Washington found that infants’ brains have a built-in ability to map their own body parts onto the body parts of the people around them. A baby recognizes, on a neural level, that their lips correspond to your lips, and their hands correspond to your hands.
This body mapping is what makes imitation possible before a baby has any language. If you pucker your lips, stick out your tongue, or make exaggerated mouth movements while looking at your baby, they may try to mirror what they see. It’s not random. It’s one of the primary ways infants learn from other people in the first months of life. So if your baby purses their lips while you’re talking or making faces at them, they may simply be trying to copy you.
Sensory Exploration With the Mouth
Between about 3 and 9 months, babies enter a phase where the mouth becomes their main tool for investigating the world. This goes well beyond feeding. During this period, babies bring objects to their lips and tongue to learn about texture, shape, size, and density. The lips and tongue are packed with nerve endings, making them far more sensitive than the fingertips at this age.
From 3 to 6 months, you’ll see babies mouthing objects they can grab. Between 6 and 9 months, they become more deliberate, using both mouth and hands to examine different aspects of new objects. By 9 to 12 months, self-feeding begins to take over, and babies experience a wide variety of textures through food. Throughout this entire stretch, lip puckering, pursing, and other mouth movements are a normal part of how your baby processes sensory information. If your baby puckers while handling a toy or touching a new surface, they’re learning.
Teething and Gum Discomfort
When teeth start pushing through the gums, usually around 6 months, babies respond with a range of new mouth behaviors. Increased biting, chewing, and gnawing are the hallmarks, but unusual lip movements, including puckering and pressing the lips together, can also appear as babies react to the unfamiliar pressure and soreness in their gums. You’ll typically notice this alongside other signs like drooling, fussiness, or a strong desire to chew on firm objects. The lip puckering in this case is a response to discomfort rather than hunger or social interaction.
How to Tell the Difference
Context usually makes it clear. A newborn under 3 months puckering in their sleep or when their face is touched is likely showing a rooting reflex. Lip smacking paired with hand-to-mouth movements and restlessness around feeding time points to hunger. Puckering that happens while you’re face-to-face with your baby, especially if you’re talking or making expressions, is likely imitation. And a 6-month-old who puckers while gnawing on a teething ring or drooling heavily is probably dealing with incoming teeth.
The one thing all of these have in common is that they’re developmentally appropriate. Lip puckering in babies is not a sign of pain, neurological problems, or feeding difficulties on its own. It’s one of the first ways your baby communicates, explores, and grows.