How young is too young to know what rape is?

Let say you heard of a 11yr old boy who forced a 8yr old girl to have sex with him (as best I guess he would know what sex was) by swiping a beer from his fridge and spiking some drink and tricking her into drinking it then taking advantage of her once she is too tipsy to resist. Would you consider that rape? Him acting out on something he may have heard older boys speak about or something he may have thought he seen on TV. Do you bring in the law, or handle it quietly as to not cause a media frenzy that would embarrass the kids? Is an 11yr old and no, not mine capable of the concept of rape?