So I thought I had mice in my house. I put down some traps 2 months ago. I also have a pair of cats so I figured either way it would sort itself out. Well last night, turns out I did catch something. It was not a mouse but a vole!! Now I am confused as they don't tend to go inside homes. It is extremely rare. I felt bad so I got him off the trap and stuck him in a cage. I will be letting him go later when it is dark. It is too cold to let him out covered in oil anyways.

He accidentally found his way into my house and I want to find where the point of entry was. How do I go about doing this?