Almost all newborns start out this same way. I think the reason is because for nine months inside mom they are lulled to sleep during the daytime by mom moving around. Then at night, they are bored with all the stillness and stay awake. This pattern then continues after they are born.

This is extremely easy to change. Simply do not allow your infant to take those nice long 3-hour naps in the middle of the day. I know it is tempting (three hours of peace and quiet is a Godsend), but if you want baby to sleep more at night, your are going to have to give this up. Wake baby up after an hour or two of napping. Things will eventually turn around for you.

If you are blessed with a baby that sleeps at night AND during the day, then don't wake her up during these naps. Enjoy this while it lasts.