We’ve all been there: Your infant has been up for hours, is rubbing their eyes, fussing, and yawning, but just will not go to sleep.

It makes a parent want to pull their hair out and scream, “GO TO SLEEP!” This situation is so frustrating and commonplace that it spawned a book and website called Go the F*** to Sleep.

Without too much swearing, let’s explore why babies fight sleep and what you can do to help them.

1. Circadian rhythm

Infants start to develop their circadian rhythms, the 24-hour cycle that regulates our bodies, at around 6 weeks old. These circadian rhythms mature enough to establish a true sleep schedule at 3 to 6 months old. And of course, every baby is different, so some may not establish a real sleep schedule until after that.

How to help

  • Establish day-night behaviors by playing and interacting with them during the day, exposing them to lots of sunlight in the morning and afternoon, but being less interactive and more sedate before bedtime.

2. Overstimulation

Lots of physical activity, loud noises, or loud music before bedtime can overstimulate infants and cause them to fight sleep, especially at night. And toddlers may be overstimulated by too much screen time before bed.

How to help

  • Establish and keep a soothing bedtime ritual. Taking a bath, reading books, cuddling in a favorite chair, snuggling with a teddy or other transitional object, saying prayers, turning the lights down, saying goodnight to objects in the room — these are all ways to help ease a child to sleep. Be consistent and do the same things in the same order around the same time each night.
  • Eliminate the rough physical play and electronic devices at least an hour before bed.

3. Overtired

Babies sometimes have a narrow window in which they will optimally fall asleep. Waiting until this window has passed often leads to a state referred to as being “overtired.” This can occur before nap times or at night.

How to help

  • Watch closely for signs that your baby is tired and put them to bed within minutes of signs like rubbing eyes with the back of the hand, yawning, fussing, or losing interest in play.

4. Not tired enough

Conversely, as your baby gets older, they may need less sleep. You may be putting them down at the same time as before, but they may not be ready to sleep yet.

How to help

  • Wait for signs that your baby is tired before putting down for a nap.
  • Gradually push back the bedtime if you notice your baby is consistently not ready to sleep at night.

5. Napping too late in the afternoon

This is directly related to number 4. Sometimes, the reason your baby is not ready for bed is because they just recently woke up from a nap.

How to help

  • Lengthen the time between waking after the last nap of the day and bedtime.

6. Hunger

Young infants need to be fed very frequently. But no matter the age of your infant, you may have better luck for sleep at night if you feed them at specific times.

How to help

  • Feed your baby between 10 p.m. and midnight, as one study of breast-fed infants showed this helped to lengthen nocturnal sleep between midnight and 5 a.m.

7. Separation anxiety

Often seen around 7 to 9 months, your baby may fight sleep because they don’t want you to leave.

How to help

  • Play peek-a-boo and games in the mirror to help them understand that you can go and come back.
  • Whenever you leave your baby to go into another room, tell them, “I’ll be right back.”
  • If you leave for the evening, try to use the same babysitter.

Next steps

Of course, if you’ve tried these maneuvers and they don’t seem to be working, talk to your doctor.

Watching your baby fight sleep, which is often when you are exhausted yourself, can be very frustrating. But most of the time, they respond to one of the interventions above.