Girls often dont discover their vulva (female external genitalia) until about ten to eleven months of age. They may even insert objects into their vaginas as a matter of curiositymuch like the beans and small toys children of this age like to put into their noses and ears.
Genital play in both sexes can also take the form of rubbing with hands or rubbing against other objects such as a pillow, stuffed animal or the bed. Often the child will be found staring, flushed, with an absent look on their faces, breathing fast or irregularly while masturbating. The behavior generally increases with boredom, sleepiness or stress in the childs life. It is important to remember that
children do not generally associate this activity with sexuality or adult relationships until much later in childhood, more toward puberty. This is reassuring to some parents who are alarmed by their childs behavior. Genital play is often used simply as a form of self-comfort.