This is really just wild speculation, but I wonder... since pre-scenting a room can be so successful in getting a snake ready to eat at mealtime.... what effect does it have to have the snake in the same room as the rats where the smell is always there? It might stimulate the appetite, or it might dull the snake's senses to the smell, or it might let the snake think food is always around, I don't need to worry about eating right now.