On his way over to Billy, Drake picks up an unconscious guard and slings him over his shoulder for a demonstration. "Hey Billy, Next time you eat someone, try it like this."  Trying to ignore the blood spread across the floor from BIlly's kill, he grabs the guard off his shoulder, tilts his head back, slips him into his throat, and swallows.  "See.  Easy, quick, and no mess or evidence."