Grand Vulcana
4–6 months
From the shallows you hear it before you see it. A rumble.
The ground feels different underfoot. Warmer. More alive. You follow the sound inland and the landscape opens into something enormous.
A caldera. Ancient, powerful, awake.
Steam rises from vents in the earth. The ground shifts constantly, not violently but persistently, as though something huge is happening just below. It is.
This is what parents call the four-month regression. Here's what that phrase leaves out: you're not going backward. You're standing on ground that's being remade.
Sleep architecture reorganizes from the bottom up. New cycles form. The baby who used to sleep through anything now notices everything. Every transition. Every shift in the earth. They wake. They cry. They feel all of it.
But look closer. Magma cools into stone. What's being built here is permanent. The rumbling settles, and when it does you're standing on new ground: stronger, more complex, closer to how an adult sleeps. This isn't a disaster zone. It's the birth of something.
Most babies in Grand Vulcana are 4 to 6 months old.
- Naps
- 3 to 4, moving toward 3
- Wake windows
- 90 to 150 minutes, growing across the stage
- Nights
- 10 to 12 hours with one to three wakings
Anchor bedtime to the rhythm, not the clock.
The biological window for sleep is real now. An evening bedtime that follows the last wake window beats a fixed hour, at almost every age from here.
The swaddle comes off before rolling begins.
The moment any sign of rolling appears, swaddling stops. That's a safety requirement, not a preference. A graduated exit, one arm then both, works for most babies.
Practice settling at the morning nap.
Your baby's brain can now start building the skill of getting past a cycle boundary alone. The morning nap is the easiest place to start.
The forty-five minute nap.
Dark room, steady sound, the wake window was right. It still ends at forty-five minutes. Short naps are ordinary at this stage, and they tend to lengthen on their own.
The swaddle exit.
Rolling is starting and the swaddle has to go. The graduated exit is more manageable than most parents expect.
Bedtime is running late.
Without an anchor, a lot of babies arrive overtired and settle harder. Bringing it earlier often shows up the same night.
Always on the back to sleep
If your baby rolls onto their front on their own, you don't need to move them back. But the swaddle comes off the moment any rolling sign appears
Firm flat surface, fitted sheet only
Room-share until at least six months
No loose bedding, pillows, bumpers or soft toys in the sleep space before twelve months
Sleep has been rebuilt from the ground up, and the work you do here compounds through every stage that follows.