What happens in Wonder Weeks leap 6, and why does your baby wake up so often?
Kyra Hendrix, certified Gentle Sleep Coach® trained in the Kim West method · updated November 8, 2026
For babies around 9 months old
Wonder weeks leap 6 comes around thirty-seven weeks and is about categories: your baby learns to group things, like animals and objects. In the same period, crawling and sitting get going and separation anxiety is strong. Those new skills get practiced in bed too, and that wakes your baby up. Practicing during the day helps.
Once you see the pattern in this series, this leap is predictably hard. It combines exactly the two things that hit sleep hardest.
What changes in this leap
Leap 6 is about understanding categories: learning that things can be grouped, that a dog and a cat are both animals, that objects come in kinds.
That's the mental side. The practical side is that crawling and sitting get going in the same weeks.
And separation anxiety, which first showed up in leap 5, gets stronger here.
Why this is the second hard one
Kyra's rule about this series is that the leaps with a motor milestone hit sleep hardest, because those skills get practiced in bed. Leap 4 was rolling. This is crawling and sitting.
Think of waking up, sitting up, and then not knowing how to lie back down. Then you get called, because your baby does want to sleep, but has lost the way there.
Add the stronger separation anxiety, and you have a night that breaks open on two fronts at once.
What to do in this leap
Practice sitting and lying back down during the day, both directions explicitly. What works during the day doesn't need to be figured out at night. See milestones and sleeping badly.
Respond to the separation anxiety instead of sitting it out. Extra security is the tool here, and the baby carrier during the day helps with that.
Keep an eye on the wake windows. Around nine months they go up to two to three hours, with the longest stretch before bedtime: wake windows from 8 to 12 months.
Leap 6 symptoms: how to tell you're in it
By the three C's: more crying, clinginess, crankiness. The full approach is in Wonder Weeks and sleep.
Around forty-six weeks, leap 7 follows, with standing and walking.
Know someone going through this right now?
Send them this article with one tap.