I hadn't intended it, but the treat I left Henry last night resulted in a trail of clues to where he's hiding. Except it stops in the middle of the basement!
I'm sure nobody's ever celebrated his birthday, so I made Henry a little 'cake' (apparently mice love peanut butter).
For about a week, Henry the Mystery Mouse has been scurrying off with the sunflower seeds we've been putting out for him. We thought he was around, but now we know he's with us and doing fine! I bought a humane trap, but we don't really want to put him outdoors until we know the weather's not going to kill him.
I just wish he'd say hi.