Why Do Babies Sleep with Their Butt In The Air? (5 Reasons Why & Concerns About SIDS)

Babies tend to sleep in a face-down fetal position with their butt in the air in response to muscle memory developed in the womb, which is the most comfortable position for them before they learn to crawl and walk.

Your little bundle of joy looks so peaceful and content while sleeping on their knees and folded forward with that sweet little face to the side, and you probably wonder if this is normal.

Although this is such a heart-warming picture that begs not to be disturbed, mothers know that babies should sleep on their backs to maintain a clear airway.

This is true when your baby has limited muscle strength and is still in the process of developing the necessary motor skills to manage movement.

This funny butt-in-the-air sleeping position happens to be the premium sleeping position for babies who have gained muscle control and can roll over when they sleep.

Some mothers may see this adorable butt-in-the-air sleeping phenomenon as a natural sleep posture, but how safe is it really?

Let’s delve into this fun topic and see what those in the know have to say.

Baby’s knee sleeping phase

An infant baby boy is sleeping with his butt in the air

From birth, you have been swaddling your little one and placing them on their back to sleep which is the recommended sleep posture to maintain a clear airway and prevent SIDS (sudden infant death syndrome).

All this effort wasn’t in vain, because from birth, your tiny baby has had little to no muscle strength to control their head movements, never mind mastering any other dexterity skills.

Babies go through many milestones in their first year, and the excitement around each new achievement is a mind-blowing cause for celebration for many parents.

This is all part of the beauty of being able to be part of every new milestone your little one reaches.

Yes, the butt-in-the-air sleeping technique was masterfully developed by millions upon millions of babies for very good reasons, and yes, this too represents a new milestone and phase in your baby’s journey to becoming a fully independent person.

Does this unique sleeping posture ever really end? If you’re honest, then your answer will be no. It never ends, no matter how big our beds become.

On a more serious note, after months of swaddling and placing your baby on their back to sleep, your little one begins fighting against being unnecessarily swaddled and starts worming their way out of mom’s makeshift straightjacket.

Tummy time is paying off, and your little one has become stronger and more able to master basic movements like rolling over and lifting their head on their own.

Your baby’s arms and legs show signs of coordinated movements, and being the diligent parent you are, you press on with training your little warrior to rise up and begin crawling.

This too will pass as your little one conquers one milestone after the next.

Let’s examine this odd sleep posture and see what motivates little ones into this and other odd sleep positions.

Reasons why the knee sleep position is popular among babies

An infant baby is sleeping on his knees, also known as the frog sleep position for babies.

The frog sleep position is another name for the knee sleeping position. Although the elevation is not correct, the idea focuses on the legs that are folded beneath the lower abdomen.

This is the universal posture of a frog, but it is also the same posture of a human baby in the womb.

Here are some plausible reasons why babies gravitate to this awesome Kodak moment sleep position.

1. Comfort

The natural tendency to move into the knee sleep position is nothing more than your baby finding the most comfortable position to sleep.

Many adults sleep in this exact position but instead of being on their knees, they lie on their side and roll up into a ball.

We all know that baby can fall asleep anywhere and literally in any position.

Babies fall asleep sitting up and, at times, will simply flop forward into this bum-in-the-air position which to them is super comfortable.

2. Innate memory

The knee sleep position mimics your baby’s posture in the womb, so it’s safe to say that babies grow into this fetal position, providing much comfort and support during their time in the womb.

The fetal posture is imprinted in a baby’s mind and relates to comfort and security. Hence, it’s not surprising that most babies old enough to maneuver their tiny bodied will favor this sleep position.

3. Cuddle position

Babies love to cuddle, and the fetal posture is replicated here too. Think of how you position your baby when breastfeeding or holding your little one in your arm.

The same basic fetal position is used, and your baby is already accustomed to the posture from your womb.

Curling that little body in a “C” allows your baby to get closer to you for those important cuddle moments.

The “C” posture stands for everything dear to a baby, like warmth, the vibration of your heartbeat, your smell, delicious milk in your breast, and the security of your arms.

4. Freedom of movement

Moving around and exploring a whole new world is what babies do as soon as they master the skills, and babies react like magnets to anything interesting that catches their eye.

Sleeping in the knee position is like the start point of a race for babies.

As your baby wakes from this position, they will either sit upright or look around and move to whatever attracts their attention.

So, in a sense, the knee position offers an easier movement start than a back sleeping position that requires a few more steps to get going.

5. Peaceful yoga position

As you’ve probably realized by now, sleeping in the upright fetal or knee position is very normal, and you can expect this type of behavior when your little one is about six months old.

The fetal position is considered the recovery position for humans and is said to relieve stress and muscle tension in the body.

Those who practice yoga will testify to the relaxing state the basic fetal position creates.

Resting in the fetal position allows our body to spread built-up tension across the whole body, creating a state of relaxation.

Babies use the fetal position to self-soothe and relax. If you have a fussy baby who possibly has colic, you will notice how effective this posture is when trying to console the little one.

Concerns about SIDS

Looking at the timeline of baby development, babies are more at risk from accidental suffocation, which is the most common cause of SIDS during the first 6 months because they do not have the muscle strength or motor skills to move away from danger. This, however, does not mean that prevention should be relaxed.

Babies will progress from being swaddled and sleeping on their backs to being put to bed on their backs, but now they have the strength and skills to roll around and assume all sorts of funny sleeping positions.

This phase can be challenging but is essential for your baby’s development.

SIDS remains a concern, so the transition away from the security of being swaddled to free sleeping should include the necessary safety measures. Changing to a toddler sleep sack will keep your little one warm and allow room to move.

Alternatively, you can dress your baby in warm sleep onesies if you have a temperature-controlled room. Your baby’s cot must still be free of loose blankets, plush toys, and other suffocation hazards.

One thing to consider is the negative effects of sleep disruption.

If your little one chooses the frog or fetal sleep position, then putting them on their back periodically throughout the night only disrupts their sleep.

It’s best not to fight against your little one’s sleep posture choice.

Make sure your baby’s sleep environment is as safe as possible, and continue with your nightly checks to monitor your baby’s developing sleep pattern.

SIDS is mainly tied to suffocation, but many cases have presented inconclusive results, while some have been linked to underlying medical conditions.

However, we do know that SIDS is connected to a baby’s sleeping habits, and the frog posture after 6 months old presents no more danger than other “normal” sleeping postures.

The important thing is your baby should be strong enough to spontaneously move or flip over and away from a potential hazard.

As your baby develops, make a habit of talking to your pediatrician so you can get the best advice from a medical professional.

Your pediatrician knows your baby’s health history and will be able to give you the best advice specific to your little one.


What has crawling got to do with the frog sleep position?

The frog sleep position is the “ready” position of the crawling posture.

This posture represents freedom of movement, and your baby soon learns that tucking their legs and arms underneath them and moving them in the proper sequence moves them forward.

You could say that this sleep posture is part of your baby’s normal development process and will fade away with the onset of the walking phase.

Can I put my little one to bed directly into the frog position?

No, it is not a recommended practice. Instead, always put your little one to bed on their back, which will mimic the way adults get ready for sleep.

You start on your back and then move around to find the most comfortable position.

Baby will develop different sleep positions, and favorite positions will differ among babies and change over time. Stick to the basics and let your little one be to explore independence.


Our little ones never fail to charm and alarm us with their strange antics, like falling asleep flopped over in odd and uncomfortably looking positions.

The frog or fetal posture is one such sleep position that most babies enjoy for a brief period before they learn to walk.

Milestones mark the end of a development phase and the beginning of another.

For example, the frog, knee, or fetal sleeping position is comfortable for babies, and the normal posture leads to and includes the crawling phase.

Enjoy these precious moments but always remain vigilant regarding your baby’s sleep space.

If you’re in doubt at any time, speak to your pediatrician for sound advice about the best practices for your baby’s health and well-being. 

Was this article helpful?

Hi! I'm Jennely. My hands and mind can't be still; neither can my three-year-old. So I'm either chasing him or my next project. I like to work smarter, not harder. This is why I write on topics that will help parents solve problems and enjoy precious moments with their little ones.

Leave a Comment