A closer look

Despite what their deafening, middle-of-the-night siren wails might suggest, newborns are faking the waterworks. Human infants are born with functioning tear ducts, but they only produce enough moisture to lubricate the eye, not enough to actually drop a tear. It takes anywhere from four to twelve weeks for their lacrimal glands to mature enough to produce the literal tears of frustration they will rely on for the rest of their lives.