I usually leave my hides in also. If the rat goes in and stays just a little to long I will check and make sure they are ok. My boys go back and forth with size. Sometimes the small rats are to big for them. They act like they are scared of them. If they do that for a week or so I will offer a rat pup or two then go back to the small rat. I have one that won't touch a live rat he wants mice hopefully yours will take the rats