Newborns sleep an average of 17 hours a day, but usually only one or two hours at a time. By three months, most babies sleep only 15 hours, about two thirds of it at night. By six months, nearly all babies have settled down to sleeping eight or more hours at a stretch at night. As you begin to see regular sleep patterns, you can begin to establish a regular bedtime routine. There are many reasons children resist bedtime and going to sleep.
Separation anxiety is one.
Other factors include hunger, fear, illness, too much daytime sleep, changes at school or in the family and inconsistent bedtime limits. Once you get a handle on why your child is resisting, you can begin to set some guidelines and create some family ritual that will make the experience more pleasurable. It you just send the kids straight to be, they will probably have trouble falling asleep. Establish a predictable bedtime routine. This gives them a chance to fall asleep easier.