Why is your baby making smacking sound while bottle feeding

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It’s not uncommon to hear little lip smacking sounds from your bundle of joy during bottle-feeding. These sounds can be quite adorable, but they might also make you wonder about what’s going on with your baby. Let’s explore this together!

In our opinion, your baby is making smacking sound while bottle feeding because the baby is breaking the tight seal around your bottle nipple which they create with their lips. The Sound caused due to the air and the breaking of the section is what you hear.

The baby can make smacking sounds while they are awake, asleep, breast-feeding or bottle feeding.

We are discussing specifically about noise they make when they are bottle feeding ( baby smacks while bottle feeding )

We will answer all your questions about lip smacking and also help you to handle the issue in the best possible way

Some babies make clicking sounds during feeds. This is hard to distinguish from a normal sucking or smacking noise.

If you are new to bottle-feeding and want to learn more please read our Bottle Feeding :The Definitive Guide for new ( and experienced ) mothers

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Reasons why your baby could be making smacking sounds during feeding

There could be various reasons why this is happening and you will have to carefully investigate the issue and act accordingly

Some of the possible reasons for this could be-

1.It is a natural reflex

The sound is a natural reflex that may happen when your baby’s mouth or tongue touches their lips while feeding. The sounds are not harmful and will most likely get resolved over time.

2.Acid reflux

Discomfort from reflux can cause lip smacking sounds.

acid reflux

3.Teething and Sore mouth

Discomfort from new teeth or a sore mouth might lead to unusual feeding sounds like smacking.

Or it may be that your baby is experiencing pain while eating and making these sounds as a symptom of this condition

4.Tongue tie

A tongue tie is a condition where a thick tissue connects their tongue to the floor of their mouth, which restricts the movement of their tongue .

Your pediatrician or lactation consultant can help you with these problems by clipping your child’s frenulum (the part of the tongue tie)

5.Lip Tie

This is a condition where the connection between the upper lip and gum is not released. The cause of the lip tie is unknown, but it can lead to difficulties with breastfeeding/ bottle feeding because when your child sucks on a breast or bottle, their tongue presses against this tight connection which in turn restricts milk flow

If you suspect that your baby has a lip tie then speak to your pediatrician

6. The flow of milk. 

If the milk is flowing too quickly or too slowly, your baby might adjust their sucking pattern, which can lead to smacking sounds.

The main cause of the flow of milk being too fast or too slow is due to using a very high nipple setting. The Nipple flow rate has to be correct for your baby.

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You can also check out these other Slow flow Stage 0 nipples which our readers use

You should not use one bottle nipple while you are bottle feeding your baby. You can purchase nipples with different flow rates as your baby grows.

I was surprised to learn this as a new mom! .Each bottle has a range of nipple flow rate options.

When you start off your baby with the first bottle, you should choose a slow-flow nipple. Each bottle manufacturer labels nipple flow rates in different ways and it can be quite confusing. And, to confuse you further, the same flow rating doesn’t necessarily mean the same thing from one bottle brand to the other. You can start with one of the following: preemie flow, extra-slow flow, slow-flow, 0+m, 1+m, or size/level/stage 1.

Once your baby has become comfortable with bottle feeding, you can then upgrade to using stage 2 nipples or 3+ M nipples.

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Here are some other favourite Stage 2 nipples once your child has grown up a bit , which are loved by most of our readers

Babies suck differently from a bottle than they do with the breast, and it can take them just as long to figure out. You don’t want them feeling like you are flooding them while they are learning.

If your little one has progressed through nipple flow rates as advised by the bottle manufaturer (requiring an increased nipple size about every 3 months), congratulations!

If not, don’t worry–your baby may still be using a slower progression for feeding.

Pay attention to your baby’s cues to know when to adjust the flow rate.

There are various other signs of distress that may indicate that the flow rate is too fast.

On the other hand, below are signs that the flow may be too slow.


7. Poor Latch

poor latch

If you notice signs of a bad latch while you are trying to bottle feed your baby, you should gently break the latch and try to get a deep latch. 

You can also adjust positioning of the baby while feeding.

8. High arch on their mouth

Some babies have a high arch which can cause the baby to make a smacking sound while feeding from bottle.

This can cause the nipple to slip out of the baby’s mouth.

This is more common in premature babies who are not coordinated enough yet to drink from a bottle. 

If you notice this,remove the nipple and reposition it with downward pressure on top of their tongue until they open wider for better suction before giving them another try.

9. Baby playing with nipple

.As per Dr Colin Kerr, smacking lips is usually just a result of the baby generating suction around the bottle nipple, then suddenly letting it go. Sometimes it can just be the baby playing with the nipple. Nothing to be concerned about.

10. Exploring the sensation of touch

 Babies are curious little explorers! They might be playing with the nipple or discovering how different movements affect the flow of milk.

11. Wrong positions during feeds

. Try to change the positions while you are bottle feeding the baby

12. Sucking on air and milk at same time

Babies make a smacking sound while bottle feeding because they are sucking on the milk and air at the same time 

13. Baby sucking hard

It could also be that your baby is trying to suck on the bottle nipple as hard as possible in order to get milk out of it, which might make a smacking sound 

If the problem is not one of the above, you should consult Lactation Consultants

Frequently asked questions

What are the normal sounds a baby makes while feeding

While feeding babies make the following sounds

  • Gentle sucking.
  • Swallowing.
  • Inhaling.
  • Exhaling.
  • Grunting
  • clicking sound 

Does baby still get milk with a bad latch?

Without proper latching on the bottle’s nipple, your baby will not get enough milk.

If you are breastfeeding then not only will she get enough milk, but also your breasts won’t be stimulated to produce more, creating a vicious cycle of poor milk demand and poor milk supply.

Further , your  nipples can get cracked and painful when the latch isn’t right.

It is important that you get a proper deep latch while feeding.


We have covered the majority of reasons why your baby makes smacking sounds while bottle feeding.

If none of them apply in the case of your baby , you could consult your pediatrician to get a better understanding of the problem.

But as we have mentioned above, it is not a very serious problem and can be ignored in many cases.

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Carrie Walters is a young mother of Nina and Tom, who along with her husband Jake is passionate about helping moms and families find modern solutions to common parenting and lifestyle questions. Together with a team of real moms and medical experts, this young couple share sound advice and proven tips to help make your life easier.
They manage this blog along with other blogs and Youtube channels on similar topics