Does the human body really need sleep?

Why does it feel like being a mom means that you are up hours before the sun is even up and in order to have any sort of life you don't go to bed until about 5 hours after the sun has gone down? Look at the time of this post- and I have been up for about 45 minutes already. Should anyone be up at this time? I think the answer is clearly no since most of you reading this are sound asleep in your nice warm beds right now. Although, I am visiting my parents right now and since my sister is the mother of three I would expect to be seeing her cheery face any minute now. So, if any of you see me and I suddenly fall asleep- don't be alarmed it is just because I am functioning on about 4 hours of broken up sleep a night. I'm not bitter....