3 - 4 Months

Why babies put everything in their mouths

Baby chewing on a teething ring

When parents bring their children in to see speech and language therapist Lindsay Hockey, she asks: “Did your child mouth as an infant?” 

Child development professionals want babies to mouth different textures in infancy to prevent speech delays and picky eating. 

Mouthing is how babies learn

Like observing and touching, mouthing is one of the primary ways your baby investigates their world—a baby’s mouth is at the center of their tactile system. Mouthing is how they learn about sensory qualities like shape, density, texture, and taste. By 6 months, babies take in more information through their mouth than any other sense. 

Your baby’s mouthing is not only a healthy form of discovery, it’s also a sign of advancing physical and cognitive development. Grasping and bringing an object to their mouth requires your baby to coordinate their vision and motor skills.

When mouthing begins

Their own hands are the first things your baby will put into their mouth. Try putting your baby in a side lying position so their hands naturally come together in front of their face. 

At around 3 to 4 months of age, when their hand-eye coordination advances, your baby will likely start to reach, grasp, and mouth more intentionally. 

Long-term benefits of mouthing

While mouthing objects, babies experiment with different ways of moving their lips, tongue, and jaw. Studies show that these experiences can help lay the foundation for speech and prepare them to eat solid foods.

4 tips to support mouthing

  1. If your baby is not yet bringing an object to their mouth on their own, you can gently hold it there for them to lick and gum
  2. Encourage mouthing by giving your baby teethers with different textures—smooth, ridged, soft, and sticky.  
  3. Put a damp washcloth in the freezer so they can experience different temperatures.
  4. Check out our article on household items safe to mouth (and a few to avoid).

Learn more about the research

Babik, I., Galloway, J. C., & Lobo, M. A. (2022). Early exploration of one’s own body, exploration of objects, and motor, language, and cognitive development relate dynamically across the first two years of life. Developmental Psychology, 58(2), 222–235.

Berger, S. E., Cunsolo, M., Ali, M., & Iverson, J. M. (2017). The trajectory of concurrent motor and vocal behaviors over the transition to crawling in infancy. Infancy, 22(5), 681-694.

Borowitz, S. M. (2021). First Bites—Why, When, and What Solid Foods to Feed Infants. Frontiers in Pediatrics, 9, 654171.

Iverson, J. M. (2010). Developing language in a developing body: The relationship between motor development and language development. Journal of Child Language, 37(2), 229-261.


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Posted in: 3 - 4 Months, 5 - 6 Months, Lovevery App, Mouthing, Sensory Play, Cognitive Development, Sensory Development, Child Development

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