Thumb Sucking at Night: When to Leave It, When to Stop
Thumb sucking at night is normal, and for babies and toddlers the right move is to leave it alone. The AAP says all babies are born with the need to suck, and for some it has “a soothing and calming effect.” The American Dental Association says children usually stop between two and four. Help your child stop if they are still sucking hard past about age 3 or 4, if their permanent front teeth are close, or if a dentist sees changes in their teeth or the roof of their mouth. For a baby, a thumb is a self-settling tool, and a useful one.
Why babies find their thumbs
The AAP’s page on pacifiers and thumb sucking explains the basics. Babies need the sucking reflex to feed, and sucking beyond feeding calms some of them. The ADA’s thumbsucking page adds that young children “may also suck to soothe themselves and help them fall asleep.”
That is why it shows up at night. A baby who stirs between sleep cycles and gets a thumb to their mouth can often settle again without you. Betteroo’s guide on how self-settling develops puts the timing at around 4 to 6 months. That is when sleep cycles mature and most babies can get their hands to their mouth on purpose. Before that, it says, hand sucking is “a preview, not the finished skill.”
Leave it, or help them stop? By age
| Age | What to do |
|---|---|
| Newborn to about 6 months | Leave it. It is a reflex, and it settles them. |
| 6 to 12 months | Leave it. It may be how they get back to sleep at 2 a.m. |
| 1 to 3 years | Leave it. The AAP’s first step is to “ignore them” because most children stop on their own. |
| 3 to 4 years | Watch. The AAP flags strong sucking “beyond 2 to 4 years of age.” |
| Front teeth on the way | Help them stop, and talk to your dentist. |
How hard your child sucks matters as much as age. The ADA says a child who rests a thumb passively in the mouth is less likely to have problems than one who sucks vigorously.
The carrier, the swaddle and the thumb
This is where babywearing comes in, because the carrier is often where a baby first discovers their hands.
In the carrier. An upright, tummy-to-tummy carry puts your baby’s hands close to their face. Plenty of babies suck a fist or a thumb while worn, and that is fine. The airway rules still come first. The AAP’s carrier guidance says to check that your baby’s “mouth and nose are not blocked by fabric or your body.” A hand at the mouth should not hide it from you. Keep the face visible and the chin off the chest, as in babywearing safety.
When they doze off sucking. A thumb does not make carrier sleep any safer. The AAP’s safe sleep guide says a baby who falls asleep in a carrier or sling should be moved “to a firm sleep surface on their back as soon as possible.”
Coming out of the swaddle. A swaddled baby cannot reach their hands. The AAP says to stop swaddling “when your baby looks like they’re trying to roll over,” which usually happens around 3 to 4 months. Many babies find their thumb soon after their arms are free.
Why a thumb can help a contact napper
If your baby only naps in the carrier or on you, a thumb is one thing they can bring with them to the crib. Warmth, your heartbeat and the motion of the walk all stay with you when you lay them down. The thumb comes too. So if your baby happens to be a thumb sucker, do not take it away during the carrier-to-crib transfer: leave their hands free to find it. Our guide to the baby who will only sleep on you breaks down the other things a carrier supplies and which ones a crib can copy.
Thumb or pacifier at night?
The AAP suggests offering a pacifier at nap time and bedtime because it lowers the risk of SIDS. If you are breastfeeding, it suggests waiting until breastfeeding is going well. There is no reason to swap a baby’s thumb for one, though. The two differ in a few ways:
- Teeth. The ADA says pacifiers affect the teeth “essentially the same ways” as thumbs, “but it is often an easier habit to break.” You can take a pacifier away; a thumb is always there.
- Night waking. The AAP warns that a baby who needs a pacifier to fall asleep “may wake up when the pacifier falls out” and may need you to put it back. A thumb never falls out of the crib.
- Safety. Never tie a pacifier to the crib, or around your baby’s neck or hand. The AAP calls that “very dangerous.”
How to help an older child stop
When it is time, the AAP and the ADA agree on a gentle approach. Night sucking is usually the last part to go.
- Start by ignoring it. The AAP says most children stop on their own, and that “harsh words, teasing or punishment” upset children and do not work.
- Praise the times they do not suck. The AAP suggests praise, rewards, star charts and gentle reminders, “especially during the day.” The ADA also says to praise your child for not sucking.
- Look for the trigger. The ADA says children often suck “when feeling insecure or needing comfort.” Deal with what is upsetting them before you work on the habit. If it is boredom, the AAP suggests keeping their hands busy.
- Let them choose. For an older child, the ADA suggests involving them in choosing how to stop.
- For the night, give the hand something else to do. Once your child is past their first birthday, a small comfort object can take over some of the soothing. Betteroo’s guide on when a lovey becomes safe explains why the crib stays bare until 12 months.
- A reminder, if nothing else works. For a child who wants to stop, the ADA suggests reminding them of the habit by bandaging the thumb or “putting a sock on the hand at night.”
- Bring in the dentist. The ADA says a dentist can encourage your child and explain what could happen to their teeth. The AAP and the American Academy of Pediatric Dentistry both say a mouth appliance is an option some dentists recommend.
The AAP’s reassurance is worth repeating: putting too much pressure on your child to stop “may cause more harm than good.”
The dry aside: the thumb is the only piece of baby gear that never needs washing, packing or a spare.
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When to talk to your dentist or pediatrician
- Changes in the mouth. The AAP says to talk to your pediatrician or pediatric dentist if you see changes in the roof of your child’s mouth or in how the teeth line up.
- Past about age 3. The American Academy of Pediatric Dentistry says that if a child is still sucking past age three, a pediatric dentist may recommend a mouth appliance.
- Permanent front teeth. The AAP says that if a child stops before the permanent front teeth come in, there is a good chance the bite will correct itself.
FAQ: thumb sucking at night
Should I stop my baby sucking their thumb at night? No. For babies it is normal soothing, and it often helps them get back to sleep. The AAP’s advice is to ignore the habit at first, because most children stop on their own.
Can my baby suck their thumb in the carrier? Yes, as long as you can still see their face and their mouth and nose are clear. If they fall asleep, move them to a firm, flat surface on their back.
At what age does thumb sucking become a problem? The AAP flags strong sucking beyond 2 to 4 years, and the ADA says most children stop between two and four. Gentle resting of a thumb is less of a concern than hard sucking.
Is a thumb or a pacifier better for teeth? The ADA says they affect teeth in much the same way, but a pacifier is often an easier habit to break.
