With the male humans in my life, I will always offer food. They always take it. With my snake boys, if I have to throw it away because it spoils, I will. With my snakes, I will try 3 times. Heat it, offer it. If they don't accept, I repeat the next day. After the third day, the mouse/rat gets to the garbage. I've not seen any of them go past two weeks. Remember that snakes do not see as much as they sense heat and movement. I always do a puppet show, swinging their food right in front of their face to make them strike. It works!