It's common for babies to suck or chew on their hands because they explore the world through their mouths as they develop. By 4 months of age, when teeth begin to erupt, they may use their fingers to relieve gum discomfort and itching, and may also suck on their fingers to self-soothe. Sometimes babies will suck on their hands to self-soothe even when they are not hungry.
Within 1 month after birth, newborn babies can usually only see things within 30 centimetres, and before 2 months, they can only see things in black and white. Parents can use black and white picture cards or combine them with simple stories to stimulate their baby's hearing. After 2 months, they can see colourful things so parents can now use coloured pictures, but be careful not to use too many colours to avoid over-stimulating their eyes.
If a baby who is about 1 month old smiles at you, it may be just a natural reflex action and does not represent the baby's happy mood. After two months, as babies' brains and nervous systems develop, they develop "social smiles" in response to visual stimulation, such as when being held or played with by their parents.
Babies crying does not always mean they have actual needs, sometimes they just want to give themselves appropriate stimulation and self-soothe. Crying is a healthy expression and an exercise in physiological functions. When babies cry, parents can first rule out if their basic needs are met and then consider whether they need to comfort or accompany them.
Babies before 6 months old may be awakened by the spasms of their hands or body, and sometimes are startled by sound or light stimulation. The startle or Moro reflex, usually goes away after 5 or 6 months.
Most babies will have bow legs (or genu varum) before they are 2 years old, which is normal. When a baby is born, the bones will bend to form O-shaped legs, but usually they will gradually turn into X-shaped legs or knock knees (genu valgum) after 2 to 3 years old, and will slowly straighten when the child is about 6 years old. Unless it is a pathological abnormal bone development, parents do not need to worry too much.
