It depends on the corn. Most will take it right away, others it takes a little longer. All but one of mine will eat right away. But I have an adult lavender who has to be left alone in the closet overnight with her mouse (f/t of course) for her to eat. He may also not want to eat. You can try leaving him in a dark place overnight. If he hasn't eaten it then, then he's probably not going to, maybe he's in shed?