Smiling is universal. A baby's first smile happens at about the same time in all cultures, so get ready for your baby to reward all your loving care with a beaming, toothless, just-for-you grin. This will probably make your heart melt, even if you've just had your worst night yet.

Head's up!

Your baby's neck muscles are getting stronger. He or she may even be able to hold his or her head up for short periods and turn it from side to side. You may notice this more when your baby is sitting in a car seat or strapped into a front carrier. Head control is a crucial skill because it's the foundation of all later movement, like sitting up and walking.

Sound asleep

Your baby may start sleeping longer at night (maybe four to six hours in a row) sometime between 6 weeks and 6 months of age. It's a broad range, and highly individual from baby to baby.

Most sleep experts suggest putting your baby to bed while he or she is awake but drowsy. This helps babies learn to fall asleep on their own, a skill that will come in handy for you both when he or she wakes in the wee hours of the night. You can help your baby reach that milestone sooner rather than later by establishing healthy sleep habits from the start, such as a bedtime routine with a calming bath, a baby massage, or a bedtime story.

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