For the first several months of its life, a baby's sleep patterns are different than that of its parents. Babies sleep most of the day, but they awaken every two to four hours to be fed. As a result, they cycle through the phases of sleep faster than an older child or adult who is sleeping only during the night for seven or eight hours.
Stage One: Drowsiness
In stage one of a baby's sleep cycle, the baby begins to get tired and doze in and out. The eyes droop and open and close.
Stage Two: Light Sleep
In stage two, the baby enters light sleep during which he is still aware of sounds and movements and may startle or awaken easily.
Stage Three: Deep Sleep
During stage three, the baby is in a deep sleep and will not awaken easily. The baby is likely completely still and quiet.
Stage Four: Very Deep Sleep
Stage four, very deep sleep, is similar to stage three in characteristics. The baby is still very still and quiet.
REM
A baby cycles through the first four stages in the following order: First, second, third, fourth, third, second. Finally the baby enters REM or Rapid Eye Movement sleep. REM is a period of light sleep in which dreaming may occur and during which the eyes move back and forth under the eyelids. Babies spend about half their time in REM sleep.
