Sleep Basics

Reading Sleep Cues

Your baby is talking to you — long before they have words. Learning to hear them changes everything.

If you win the baby sleep lottery, you have a baby who just dozes off when they are tired. Those babies are one in a million. I certainly didn't get one of those. My first was ALL FOMO ALL THE TIME — wide-eyed and wired when I was certain she had to be exhausted.

I was missing her cues.

Babies can't tell us they feel tired with words. We have to carefully observe them for signs that they're ready to sleep. The tricky part is that sleep cues can look a lot like hunger, overtiredness, overstimulation, or discomfort. Learning to decipher your baby's cues takes a little investigation.

Here's the most important thing to understand: every baby's sleep cues exist on a spectrum — from early (your baby is just getting sleepy) to late (your baby is overtired and has gotten a hit of cortisol to keep them going). The earlier you catch them, the smoother the transition to sleep will be.

The Cue Spectrum

Early Cues

The Sweet Spot

This is when sleep pressure — the biological drive to sleep — is just beginning to kick in. Your yellow light. Catch it and you get a smooth landing.

Glazed eyes — not focusing on anything, zoned out
Slowing down — less reaching, grasping, or kicking than usual
Social withdrawal — less interested in eye contact or your voice
Quieting down — a chatty baby suddenly goes calm and still
Rubbing eyes or ears — especially in younger infants
Red eyebrows
A subtle yawn or two

MOMally Tip Think of early sleep cues like a yellow light. Your baby is telling you: I'm getting ready. Help me get there smoothly. Dim the lights. Turn on white noise. Start a feeding if that's part of your routine.

Late Cues

When the Window Has Closed

When early signs are missed, the brain signals the body to release activating hormones to keep going. An overtired baby's nervous system is now working against sleep.

Younger babies

Intense fussing or crying — escalates quickly, doesn't respond to soothing
Arching the back — body is tense and dysregulated
Repeated yawning — jaw-wide, clustered
Glazed, red-rimmed eyes — heavy and pink even without crying

Older babies, toddlers & preschoolers

The "second wind" — suddenly wired and playful again
Clumsiness — increased stumbling, loss of coordination
Meltdowns over small things — a toy falls and the world is ending

MOMally Tip If your baby seems overtired and wired at the same time, trust the tired. Skip the extra stimulation, shorten your routine, and soothe immediately.

The Science Behind It

Your baby's sleep is governed by two powerful biological forces.

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Circadian Rhythm

Your baby's internal 24-hour clock, which helps differentiate between day and night. This system typically takes about three months to fully develop.

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Sleep Pressure

The gradual build-up of adenosine — a natural, sleep-inducing chemical. The longer your baby stays awake, the higher the pressure, and the stronger the drive to sleep.

Catching early sleep cues means you capitalize on peak sleep pressure before cortisol enters the picture. The payoff: a baby who settles more easily, falls asleep faster, and often sleeps for longer stretches.

When those early signs are missed, the brain is smart and reacts. It signals: you didn't go to sleep, so here are some activating hormones to keep you going. In a baby, those hormones make the entire process much harder — leading to what looks like "fighting sleep," where a baby is clearly exhausted but their eyes are wide open.

This is why sleep consultants frequently advise putting them down earlier. An earlier, well-timed sleep is almost always better than a later, overtired one.

Catching the Window

Now that you know what to look for, here's how to put it into practice.

Watch the clock and your baby. Use wake windows as a guide, but let your baby's actual behavior lead.

Start your wind-down early. Begin dimming lights and quieting the environment 10–15 minutes before you expect the early cue window — not after you see the cues.

Create a consistent pre-sleep environment. Dim lights, white noise, calm voices. Your baby's nervous system learns the transition cue over time.

If you miss the window, adjust — don't abandon. Add more support and expect it may take longer. Missing it once is not a disaster.

Track for patterns. A sleep app or a simple notes app can help you spot your baby's natural rhythm across a few days.

Don't test the limits. If your baby seems tired, trust it — even if the "schedule" says it's too early.

If you're reading this at midnight wondering how you got here: you haven't done anything wrong.

Babies don't come with instruction manuals, and sleep cues are genuinely hard to read — especially when you're running on three hours of sleep yourself. Learning to tune into your baby's cues takes time, and it gets easier. Every parent who has ever figured this out started exactly where you are: confused, tired, and searching for answers.

You're already doing the right thing by paying attention.

If sleep feels consistently hard — not just an occasional rough night but an ongoing pattern — a personalized consultation can make a world of difference.

Book a MOMally Consult

Andrea Scannell is a certified pediatric sleep consultant, not a medical doctor. This content is for educational purposes only. Always consult your child's pediatrician with any medical concerns.