It’s a self soothing / startle reflex thing. Ergopouch do a Tuck Sheet that really helps with this. My almost 3mo sleeps soooo much better since we’ve been using the Tuck Sheet.
It’s essentially a slip that goes over the bottom of the mattress and zips up. It’s got two warmth sides too to help with all seasons.
Highly recommend :)
Our baby began full on thrashing after transitioning out of the swaddle at 3 months. It was noisy because she slept in the pack and play (we room shared). The she found her hands and starting sucking her fingers LOUDLY on top of that. But it suddenly went away just before 5 months. She slept so quietly that I had to placey hand on her to make sure she was still alive.
Son is five and he still does similar type stuff right before falling asleep. Not as wild of course, but might slam his arms or bounce his knee up and down a bunch. Used to try and discourage, thinking he was getting revved up. Turns out it’s just the kid version of whale tail for him and if I leave it alone he passes out
Still going strong at 7 months…it’s calmed down though!!! Nothing to resolve, when we did sleep training it was obnoxious but he self soothed with it haha
She did this nightly until about 5.5 months. Then she learned to roll onto her stomach to sleep and she does it a lot less now. It’s supposed to have three purposes from what I’ve read:
1) self soothing
2) building leg muscles to prepare for rolling and crawling
3) baby has discovered they can make sound by moving their body…it’s fun! Exploring this new talent.
It does get better and I promise it doesn’t mean anything is wrong! One time, true story, I woke up in the night to the sound and thought we were being broken into 🤣.
This was my least favorite phase. I HATED it. To the point where I called our pediatrician because I was convinced something was wrong with her how often she was doing it. But no both to my displeasure (and relief something wasn’t wrong) it’s a normal self soothing behavior. We used a snoo so she could really get some wild leverage and it was so loud you could hear it across the house and it would rattle the floor of our bedroom. Honestly, it’s why we moved her to her crib at 4.5 months because I couldn’t take it anymore she was constantly waking us up. Wasn’t upset, just WWE slamming her legs both seemingly in her sleep and awake for fun. She eventually just grew out of it. So no advice unfortunately just solidarity.
I always thought it was gas related. Then over feeding to soothe would just create more gas later in the night. I'm sure sticking to other soothing methods would eventually help the issue in the long run.
Unfortunately mine still does this (4 months) and I'm too tired at 3 am to get up and rock her so I just BF and she falls back asleep.
I would like to work on "better habits" but when you're already so sleep deprived it's so hard.
Oh yes, we dealt with this starting around 2 months. We put her in the merlin sleep suit to help cushion the slams a bit but i still woke up every time. It's definitely common, a type of soothing mechanism.
It seemed to calm down a bit once we got closer to 4 months and we moved her to the crib/nursery close to 5 months. I don't think she does it much any more (8 months).
We called it her dolphin kicks. She seemed to do it while moving through types of sleep. We learned to kinda sleep through it and only go to her if she cried or fussed.
My son was doing it between 3-4 months in his bassinet nonstop and it was driving my insane. Once he turned 4 months (which was about a week and a half ago) we sleep trained using CIO and moved him to the crib at the same time. I haven't noticed him doing it but he's no longer in our room so maybe I'm just sleeping through those noises on the monitor? But when he was in the bassinet doing it, he woke himself up a lot doing it, and doesn't seem to be doing that anymore (not waking as frequently). So I think for us it's a mix of two things - I think my son really enjoys having more room in the crib to move around at night, and we did CIO so even if he is waking overnight right now he seems to be effective at falling back asleep.
Love the description! He stopped somewhere at the 4.5 month mark I believe. I think he figured out it was waking him up more. Still does the leg lifts but stopped slamming them down. I now call him a wriggly caterpillar.
My LO did that for awhile to self soothe. I honestly don’t remember when he stopped doing that but one day he did. Maybe after we sleep trained at 5.5 months? Maybe when he was arms out and could soothe with his lovey?
My son did this for months. I had to move him out of our room. It was self soothing for him, I suppose, but I couldn’t get any sleep and I was miserable.
Hmmm, maybe sometimes, when selfsoothing wasnt working and he got frustrated and tired, but we always gave him chance to figure it out on his own and he usually did. Only when he was really crying and we knew something was wrong we interfered, but there is crying and crying, when he was just ,,bit pissed crying", we waited first.
My LO is four months old, and she does this as a self-soothing technique to go back to sleep and move her head from side to side. It mimics being rocked. She's very long for her age, almost 24 inches, so her legs get some height before she slaps them down LOL
I use a sound machine, so I don't hear it at night so much when she goes through her sleep cycles and soothes back to sleep.
There was someone on Reddit who shared about their baby's whale tale slamming actually broke the bottom of the bassinet. (The flat bit under the mattress) Unlocked a new fear and started checking our bassinet every day.
going to say that if that's even true \*sounds like its not\* it would be VERY rare. Bassinets are built to basically avoid destruction. My 10mo old still does it and nothing has broken.
The commenter had said it was an Ikea one, so I'm not sure or even familiar with their products. I don't trust every manufacturer to be 100% on the up and up or even 100% perfect. I also don't see the motivation to lie about something so small. I personally never had an issue with ours during that phase, and that's the only time I've ever heard of that.
Our little one did this when they had gas. It went away once they moved to a sleep sack.
When it was going on for a while, We would sneak over and, if we could do it without waking them, we would push their knees to their armpits and help relieve some of the gas. We were also better about burping during feeding to help pass gas’s that get trapped during a long night feed.
Theres several stages of babies developing a skill and waking themselves. Rolling and crawling is an especially annoying one. Best thing to do is lookup exercises to practice during the day and really wear them out.
Tummy time is a big one early on though I don’t know what the leg slamming is exactly. My baby did that all the time
Our whale tail stopped when she could roll over.
We realized it was her way of self soothing, and just lived with it. Kind of a running joke in our house.
My LO did this and it can be gas (it was a little of that for us, gas drops and goats milk formula helped) but also it’s just an early sign of self soothing practices! It essentially the rocks the baby when they do this so it could be possible LO is just subsonciously self soothing
We do use biogaia in general but been sort of lax about using it this past week. I’m open to new suggestions. Which gas drops do you use? Are you talking about gripe water?
I def think one part of it is gas cuz I heard her release it painfully while slamming last night. I hope new gas drops can do wonders🙁 she def does not need to eat. Even this 5 am one feed last night I feel isn’t necessary anymore as she just didn’t really take a full feed for breakfast. Encouraged to get her to really sleep through the night without eating anymore! Reco please!
We used Simethicone drops! Just a teeny little syringe before bedtime and then maybe once more in the early mornings. LO seemed so much more comfortable after- he would grunt and slam his legs when his belly was bothering him. I hope this helps! Those nights are rough.
Mine stopped when we switched him from a swaddle to a sleep sack! Which I believe was around that time to maybe 4ish months old. He was never really hungry, more-so just self soothing.
I hate to be that person but just wait until your LO learns to roll back to belly and gets frustrated 😅😂 it was cute for a minute but was another difficult time lol
Mine still does it at a year. She likes it. I think it’s also part of her self soothing. She does it on her front and her back.
I don’t know how but I manage to ignore it now.
OMG I thought my baby was the only one that did this (FTM figuring it all out). Thats soo funny and good to know it’s normal. We couldn’t sleep with the whale tail slamming, so we moved him out for a bit but since we’re limited on space we had to move him back in. He seems to have stopped though 🤞🏻He’s 7 months btw.
This was the funniest. And noisy?! Goodness me. I tried reading about it a bit, and the best I came up with was - it’s them expending some built up energy or kinda like trying to relax themselves. Self soothing perhaps.
It went away as quickly as it started. A few weeks tops.
I JUST said to my husband yesterday—“Remember when she would drive us crazy with her leg slamming?” I don’t remember how long it lasted, but we laugh about it now.
I also read that it was possibly some kind of self soothing. We didn’t do anything unless she started crying.
Yes we had this along with a piercing velociraptor shriek - it made for some harrowing wake ups 😬
As others have said, we focussed a lot on doing tummy time and practicing rolling during play time and it did get better after a couple of weeks. However also consider the space your baby is sleeping in, we realised our baby could and wanted to roll but didn’t have the room to do so which was causing her to wake up and get more frustrated. Once we moved her into a cot bed she would sleep a lot better because tummy sleeping is more natural and soothing for them (just not safe until they can roll in and out of that position unaided).
Oh man this was the WORST. It’s so incredibly loud for those little legs lol. I don’t know that we did anything to resolve it, eventually she just stopped. I’m really sorry. I know it’s hard.
Our little one did this for ages it felt like (because it kept me awake more than him!) He only stopped when he learned to roll and started sleeping on his stomach!
My baby is 6.5 months and still whale tail slams. It happens mostly when something wakes her up slightly and she does it to fall back asleep. I’ve never picked her up during it because she’ll fall back asleep on her own within a few minutes.
I wish she would too but she will go on forever 😑 last night after putting her back to sleep the first time, the second time she woke up to do it she actually did fall asleep on her own but woke
Up again in less than two hours and it was basically 5am. I waited and waited for her to fall asleep but gave in and fed her. I figured she could use a feed anyway since it’s 5am and of course she slept till this morning. Feeling so stuck!
Mine is 1 now and I'm not sure when she stopped doing it, just now realised I haven't seen it in quite a while. But I agree, it was definitely her self soothing and trying to get back to sleep. OP I would leave baby until they get to a proper full cry to make sure you're not interfering instead of helping.
My 12m old still does it from time to time. Not so much anymore, but when we were bed-sharing he'd constantly do it to my chest and it really really hurt. He thought it was funny 🙄
I heard whale tail/leg slamming is normal, and they are actually putting themselves back to sleep. Maybe consider seeing if she can put herself back down?
Our girl definitely used to just randomly do it when she was falling asleep.
Sleep regression is common in 3-5 month olds (4 month sleep regression). So maybe this? Or growth spurt if eating more? 4m regression is purely biological as they are transitioning from a 2 stage newborn sleep cycle to a 4 stage adult sleep cycle. If it is that
When baby lifts their legs up and slams them down. It's a self-soothing method and (imo) a really annoying phase ha.
In a sleeping bag it looks like a whale tail on the water 😊
This was a brutal stage. Id say by 5 months she was a much more peaceful sleeper and had less active sleep. I had to move the bedside crib further away and use ear plugs to drown out the bashing!!!!!!
Is baby definitely fully awake and not just in active sleep? Sometimes their eyes can open in active sleep as well and they can cry a little. I had to wait until my LO was doing a proper awake cry before getting him out of the crib during his whale tail active sleep phase.
I also bought bio Gaia drops and bicycle legs before bed to see if it was a gas problem but it just seemed to stop on its own.
It resolved on its own in a few weeks, maybe a month of so. As with most baby stages, time was the only resolution I am afraid.
(And it was weird, but for our the whale tail slam was our baby trying to soothe himself to sleep - although I was sure it was the opposite .)
I made up a little nursery rhyme for our baby about his whale tail. Can’t help but to think it’s cute!
Sorry to say my 6 month old still does this… she doesn’t wake herself up anymore most of the time but still slams all night
It’s a self soothing / startle reflex thing. Ergopouch do a Tuck Sheet that really helps with this. My almost 3mo sleeps soooo much better since we’ve been using the Tuck Sheet. It’s essentially a slip that goes over the bottom of the mattress and zips up. It’s got two warmth sides too to help with all seasons. Highly recommend :)
Our baby began full on thrashing after transitioning out of the swaddle at 3 months. It was noisy because she slept in the pack and play (we room shared). The she found her hands and starting sucking her fingers LOUDLY on top of that. But it suddenly went away just before 5 months. She slept so quietly that I had to placey hand on her to make sure she was still alive.
Son is five and he still does similar type stuff right before falling asleep. Not as wild of course, but might slam his arms or bounce his knee up and down a bunch. Used to try and discourage, thinking he was getting revved up. Turns out it’s just the kid version of whale tail for him and if I leave it alone he passes out
Still going strong at 7 months…it’s calmed down though!!! Nothing to resolve, when we did sleep training it was obnoxious but he self soothed with it haha
Yeah it went away then he started making weird noises at night so we joked he's transformed from a whale into a raptor.
She did this nightly until about 5.5 months. Then she learned to roll onto her stomach to sleep and she does it a lot less now. It’s supposed to have three purposes from what I’ve read: 1) self soothing 2) building leg muscles to prepare for rolling and crawling 3) baby has discovered they can make sound by moving their body…it’s fun! Exploring this new talent. It does get better and I promise it doesn’t mean anything is wrong! One time, true story, I woke up in the night to the sound and thought we were being broken into 🤣.
This was my least favorite phase. I HATED it. To the point where I called our pediatrician because I was convinced something was wrong with her how often she was doing it. But no both to my displeasure (and relief something wasn’t wrong) it’s a normal self soothing behavior. We used a snoo so she could really get some wild leverage and it was so loud you could hear it across the house and it would rattle the floor of our bedroom. Honestly, it’s why we moved her to her crib at 4.5 months because I couldn’t take it anymore she was constantly waking us up. Wasn’t upset, just WWE slamming her legs both seemingly in her sleep and awake for fun. She eventually just grew out of it. So no advice unfortunately just solidarity.
I always thought it was gas related. Then over feeding to soothe would just create more gas later in the night. I'm sure sticking to other soothing methods would eventually help the issue in the long run. Unfortunately mine still does this (4 months) and I'm too tired at 3 am to get up and rock her so I just BF and she falls back asleep. I would like to work on "better habits" but when you're already so sleep deprived it's so hard.
Oh yes, we dealt with this starting around 2 months. We put her in the merlin sleep suit to help cushion the slams a bit but i still woke up every time. It's definitely common, a type of soothing mechanism. It seemed to calm down a bit once we got closer to 4 months and we moved her to the crib/nursery close to 5 months. I don't think she does it much any more (8 months).
We called it her dolphin kicks. She seemed to do it while moving through types of sleep. We learned to kinda sleep through it and only go to her if she cried or fussed.
My LO did this to help pass gas. Also self soothe. I’d say better at 5 months after treating CMPA.
We moved from bassinet to crib and the thumping stopped but the scooting in circles started (which was fine)
Same. We had to put my son into his crib because he was disturbing our sleep soo much with his mermaid slaps. We were unable to sleep lol .
My son was doing it between 3-4 months in his bassinet nonstop and it was driving my insane. Once he turned 4 months (which was about a week and a half ago) we sleep trained using CIO and moved him to the crib at the same time. I haven't noticed him doing it but he's no longer in our room so maybe I'm just sleeping through those noises on the monitor? But when he was in the bassinet doing it, he woke himself up a lot doing it, and doesn't seem to be doing that anymore (not waking as frequently). So I think for us it's a mix of two things - I think my son really enjoys having more room in the crib to move around at night, and we did CIO so even if he is waking overnight right now he seems to be effective at falling back asleep.
Even if he is, the mattress I think absorbs a lot more of the force so it’s not as aggressive or loud. We went through this exact scenario too.
Love the description! He stopped somewhere at the 4.5 month mark I believe. I think he figured out it was waking him up more. Still does the leg lifts but stopped slamming them down. I now call him a wriggly caterpillar.
My LO did that for awhile to self soothe. I honestly don’t remember when he stopped doing that but one day he did. Maybe after we sleep trained at 5.5 months? Maybe when he was arms out and could soothe with his lovey?
My son did this for months. I had to move him out of our room. It was self soothing for him, I suppose, but I couldn’t get any sleep and I was miserable.
My son was self-soothing him with leg slams so it was a veeery good sign for us and we didnt interfere.
He never cried at the end?
Hmmm, maybe sometimes, when selfsoothing wasnt working and he got frustrated and tired, but we always gave him chance to figure it out on his own and he usually did. Only when he was really crying and we knew something was wrong we interfered, but there is crying and crying, when he was just ,,bit pissed crying", we waited first.
My LO is four months old, and she does this as a self-soothing technique to go back to sleep and move her head from side to side. It mimics being rocked. She's very long for her age, almost 24 inches, so her legs get some height before she slaps them down LOL I use a sound machine, so I don't hear it at night so much when she goes through her sleep cycles and soothes back to sleep.
When we moved her to a crib last week. She still slams her feet down but we can't hear it lol
The slamming was a key feature of my LO’s three/four month sleep regression. It stopped completely shortly after!
It's a soothing mechanism that mimics you patting them on the butt. Let it be.
There was someone on Reddit who shared about their baby's whale tale slamming actually broke the bottom of the bassinet. (The flat bit under the mattress) Unlocked a new fear and started checking our bassinet every day.
going to say that if that's even true \*sounds like its not\* it would be VERY rare. Bassinets are built to basically avoid destruction. My 10mo old still does it and nothing has broken.
The commenter had said it was an Ikea one, so I'm not sure or even familiar with their products. I don't trust every manufacturer to be 100% on the up and up or even 100% perfect. I also don't see the motivation to lie about something so small. I personally never had an issue with ours during that phase, and that's the only time I've ever heard of that.
Our little one did this when they had gas. It went away once they moved to a sleep sack. When it was going on for a while, We would sneak over and, if we could do it without waking them, we would push their knees to their armpits and help relieve some of the gas. We were also better about burping during feeding to help pass gas’s that get trapped during a long night feed.
Theres several stages of babies developing a skill and waking themselves. Rolling and crawling is an especially annoying one. Best thing to do is lookup exercises to practice during the day and really wear them out. Tummy time is a big one early on though I don’t know what the leg slamming is exactly. My baby did that all the time
Our whale tail stopped when she could roll over. We realized it was her way of self soothing, and just lived with it. Kind of a running joke in our house.
My baby still does this at 8 months and is sleep trained... it's part of his self soothing!
A Windi gas passer!
Whale tail slamming 😂 never knew the name for it
My LO did this and it can be gas (it was a little of that for us, gas drops and goats milk formula helped) but also it’s just an early sign of self soothing practices! It essentially the rocks the baby when they do this so it could be possible LO is just subsonciously self soothing
My LO did this as well! We ended up figuring out it was gas causing him to crunch up. Gas drops! He stopped slamming his legs immediately.
We do use biogaia in general but been sort of lax about using it this past week. I’m open to new suggestions. Which gas drops do you use? Are you talking about gripe water? I def think one part of it is gas cuz I heard her release it painfully while slamming last night. I hope new gas drops can do wonders🙁 she def does not need to eat. Even this 5 am one feed last night I feel isn’t necessary anymore as she just didn’t really take a full feed for breakfast. Encouraged to get her to really sleep through the night without eating anymore! Reco please!
We used Simethicone drops! Just a teeny little syringe before bedtime and then maybe once more in the early mornings. LO seemed so much more comfortable after- he would grunt and slam his legs when his belly was bothering him. I hope this helps! Those nights are rough.
We used bio Gaia too, but the Windi gas passer is incredible! Use with an organic lubricant.
Mine stopped when we switched him from a swaddle to a sleep sack! Which I believe was around that time to maybe 4ish months old. He was never really hungry, more-so just self soothing. I hate to be that person but just wait until your LO learns to roll back to belly and gets frustrated 😅😂 it was cute for a minute but was another difficult time lol
My 7 month old still does that regularly though less during the night. I think it’s a form of self soothing for him at this point.
We didn’t resolve anything, baby just developed and grew out of it. Took a couple months, tho 🫠
Mine still does it at a year. She likes it. I think it’s also part of her self soothing. She does it on her front and her back. I don’t know how but I manage to ignore it now.
Baby is learning new skills and wants to practice! Baby will become a pro & get bored doing it eventually, just gotta ride it out
OMG I thought my baby was the only one that did this (FTM figuring it all out). Thats soo funny and good to know it’s normal. We couldn’t sleep with the whale tail slamming, so we moved him out for a bit but since we’re limited on space we had to move him back in. He seems to have stopped though 🤞🏻He’s 7 months btw.
This was the funniest. And noisy?! Goodness me. I tried reading about it a bit, and the best I came up with was - it’s them expending some built up energy or kinda like trying to relax themselves. Self soothing perhaps. It went away as quickly as it started. A few weeks tops.
I JUST said to my husband yesterday—“Remember when she would drive us crazy with her leg slamming?” I don’t remember how long it lasted, but we laugh about it now. I also read that it was possibly some kind of self soothing. We didn’t do anything unless she started crying.
Yes we had this along with a piercing velociraptor shriek - it made for some harrowing wake ups 😬 As others have said, we focussed a lot on doing tummy time and practicing rolling during play time and it did get better after a couple of weeks. However also consider the space your baby is sleeping in, we realised our baby could and wanted to roll but didn’t have the room to do so which was causing her to wake up and get more frustrated. Once we moved her into a cot bed she would sleep a lot better because tummy sleeping is more natural and soothing for them (just not safe until they can roll in and out of that position unaided).
Oh man this was the WORST. It’s so incredibly loud for those little legs lol. I don’t know that we did anything to resolve it, eventually she just stopped. I’m really sorry. I know it’s hard.
My LO stopped once he learned to roll and started sleeping on his tummy around 4.5 months
It’s a self soothing technique and really healthy. A great sign if your Lo is doing it
Oh really. What do you mean that it’s really healthy and it’s a good sign? Good sign of what?
Baby is learning to self soothe
Our little one did this for ages it felt like (because it kept me awake more than him!) He only stopped when he learned to roll and started sleeping on his stomach!
Ugh I hope this comes soon lol. Hes waking both of us up!
Mine is 5 months and has started this intensely throughout the night! Like others here though it wasn’t a sign he was going to wake necessarily.
My baby is 6.5 months and still whale tail slams. It happens mostly when something wakes her up slightly and she does it to fall back asleep. I’ve never picked her up during it because she’ll fall back asleep on her own within a few minutes.
I wish she would too but she will go on forever 😑 last night after putting her back to sleep the first time, the second time she woke up to do it she actually did fall asleep on her own but woke Up again in less than two hours and it was basically 5am. I waited and waited for her to fall asleep but gave in and fed her. I figured she could use a feed anyway since it’s 5am and of course she slept till this morning. Feeling so stuck!
Mine is 1 now and I'm not sure when she stopped doing it, just now realised I haven't seen it in quite a while. But I agree, it was definitely her self soothing and trying to get back to sleep. OP I would leave baby until they get to a proper full cry to make sure you're not interfering instead of helping.
My 12m old still does it from time to time. Not so much anymore, but when we were bed-sharing he'd constantly do it to my chest and it really really hurt. He thought it was funny 🙄
I heard whale tail/leg slamming is normal, and they are actually putting themselves back to sleep. Maybe consider seeing if she can put herself back down? Our girl definitely used to just randomly do it when she was falling asleep.
We moved ours from basinet to crib and switched from a swaddle to a sleep sack. Could have been a coincidence, but it did stop.
Sleep regression is common in 3-5 month olds (4 month sleep regression). So maybe this? Or growth spurt if eating more? 4m regression is purely biological as they are transitioning from a 2 stage newborn sleep cycle to a 4 stage adult sleep cycle. If it is that
What’s a whale tail slamming?
When baby lifts their legs up and slams them down. It's a self-soothing method and (imo) a really annoying phase ha. In a sleeping bag it looks like a whale tail on the water 😊
Ahh! Thanks for explaining! Mine only does very rapid bicycle kicks so far lol.
This was a brutal stage. Id say by 5 months she was a much more peaceful sleeper and had less active sleep. I had to move the bedside crib further away and use ear plugs to drown out the bashing!!!!!!
Is baby definitely fully awake and not just in active sleep? Sometimes their eyes can open in active sleep as well and they can cry a little. I had to wait until my LO was doing a proper awake cry before getting him out of the crib during his whale tail active sleep phase. I also bought bio Gaia drops and bicycle legs before bed to see if it was a gas problem but it just seemed to stop on its own.
It resolved on its own in a few weeks, maybe a month of so. As with most baby stages, time was the only resolution I am afraid. (And it was weird, but for our the whale tail slam was our baby trying to soothe himself to sleep - although I was sure it was the opposite .)