We all know that when a host is hit by a facehugger, they are put in a coma and a proboscis is inserted into their mouth. But if that is so the tube must go down the esophogis or the tracia, putting the embryo into in the intestinal track or the lungs. When ripley is scanned in Alien 3, it shows the burster in a cavity behind the sternum. How do the embryo's get there if they are inserted through the mouth?