Ever use the phrase "sleep like a baby"? Well, it turns out that infants may not be the deep, sound sleepers you always figured. According to researchers, babies in the first year of life spend about one-half their total slumber time in a very active dream state. The younger the baby, it seems, the more dreaming it does. In fact, recent research shows that at 25 weeks, human fetuses floating in the womb spend nearly all their time dreaming. Experts suspect that all that dreaming is needed to stimulate and develop that brand-new brain.