Why Do Babies Cry in Their Sleep? And Other Baby Facts New Parents Should Know

There is something wonderful in discovering all the amazing baby facts that reveal just how extraordinary newborns truly are. Have you ever noticed the little things your baby does, such as their unique noises or sudden movements? From odd noises to unexpected reflexes, your little one has many quirks that are completely normal. Below, we explore and answer common questions and interesting baby facts that every parent should know, including the age-old question of why babies cry in their sleep.

Why Babies Cry In Their Sleep

Newborns cry in their sleep for several harmless reasons. Babies sleep for up to 16-18 hours a day in their first year, often in short stretches. Their brains are still developing, which means they move quickly between light sleep and deep sleep. At this stage, babies may not yet recognize the difference between day and night, so they can wake or cry at any time.

Sleep patterns are especially unpredictable and fragmented during the first three months, as babies are rapidly developing and adjusting to life outside the womb.

During light sleep, small noises, muscle jerks, or dreams can trigger brief crying. Most of the time, the baby settles without waking up or needing help, and over time, they will learn the difference between day and night sleep cycles.

Why Babies Make So Many Noises

Newborns make grunts, squeaks, and snorts that can worry new parents. These sounds happen because the little ones have tiny airways and soft cartilage that vibrates as they breathe. Unless they show trouble breathing, these sounds are just part of the early stages. These types of noises are common among infants and are a normal part of their early development.

An additional fun fact: These early noises are actually the first steps in how babies will eventually learn to talk.

Why Newborns Keep Their Hands in Fists

Newborns often keep their hands tightly curled, which can concern some parents. Placing a baby's feet on a flat surface can trigger the stepping reflex, another natural response seen in newborns. This happens because of the palmar grasp reflex, a natural response that causes babies to hold on when something touches their palm. This reflex fades as their motor skills improve. By three to four months old, most babies begin opening their hands more and grabbing objects on purpose.

Why Babies Make Funny Facial Expressions

Babies often look surprised, worried, or amused for no clear reason. Hormones passed from the mother during pregnancy can still influence a newborn's facial expressions in the early days, causing subtle changes in their appearance. These expressions are caused by their immature nervous systems firing as they learn how to move their facial muscles. A newborn’s muscles react to sensations, lights, and sounds, creating expressions that may not match how they feel. It makes sense that parents see early smiles during sleep, as these are simply reflexes from developing facial muscles.

What does a baby's smile really mean?

Many new parents want to know if their baby is smiling “on purpose.” The special bond between a mother and her baby often shines through in these early smiles, strengthening their emotional connection. Early smiles, especially during naps, are reflex smiles. These smiles appear randomly as the brain practices new skills. Social smiles (smiles meant for people) usually start around 6–8 weeks and are more consistent and emotional.

Why Babies Have Unpredictable Feeding Patterns

Newborns need to eat frequently because their stomach is only about the size of a walnut. During growth spurts, babies may want to feed every two to three hours, with each feed lasting for a short period. Many blogs and lactation consultants confirm this is normal and not a sign that the mother has low milk supply.

Babies typically start trying solid foods around six months of age, which can change their feeding routines and digestion. Feeding patterns continue to evolve throughout the first year as babies grow and reach new developmental milestones.

Why Babies Hiccup So Much

Hiccups are extremely common in newborns, and can even start before birth when the baby is surrounded by amniotic fluid. They happen because a baby’s diaphragm is still growing and gets irritated easily. Most hiccups don’t bother babies or affect feeding. As the digestive system matures, hiccup episodes become less frequent.

Why Babies Have Peeling Skin

A baby's skin is extremely delicate and often peels during the first few weeks, especially on the hands and feet. Peeling is most noticeable in the first few days after birth. This is because the baby is shedding its protective outer layer from the womb. Many parents worry something is wrong, but doctors say it is a normal part of newborn skin development. Baby lotion can help, but the peeling will usually disappear on its own.

Why Babies Startle Easily

New parents often notice their baby “jumps” or throws their arms and legs out while lying down. This reaction is part of the startle reflex and is tied to the baby’s developing nervous system. Loud noises, sudden movements, or a change in position may trigger it. Swaddling or holding the baby close can reduce how often it happens.

Sometimes, the startle reflex can make the soft spots on a baby's head (areas where the skull bones haven't fused yet) more noticeable.

How Babies Begin to Socialize and Connect

Social connection starts earlier than many people think, because newborns respond to faces and voices almost right away. In the first few weeks, babies begin to notice your expressions, react to your voice, and may even copy some of your movements. Their bodies change quickly too - many babies lose their first hair and grow new hair during their first year. By about six weeks old, babies can recognize simple emotional cues, like a smile or a calm, gentle tone. Everyday moments like cuddling, skin-to-skin contact, and responding to their cries help them feel safe and loved as they learn to communicate.