I told 'em

"Anyone who knows me knows I'm an honest dog, not given to pretending things are or are not there unless they are.. or are not. I've been telling She who Must Be Obeyed for days and days that the Pesky Cat put a mouse in the pantry.
"Many's the time I've sat in there with my head cocked knowingly to one side and my clearest 'There's something in/under/behind there' look in my eyes. But did she do anything about it? I do everything she asks me to do, and more sometimes, but when I ask her to move stuff so I can get at the mouse does she do that for me? No.
"So is it any wonder that she gets a surprise when she checks over the stored apples?
"And to make matters worse by the time she called me the mouse had run out of its nest and gone under/in/behind something else. And still she wouldn't move stuff for me to get it. I could get it I know I could - if only she'd move stuff.
"That was yesterday. Then today when I went in to check, I heard it run under the boxes again. I told her when she came in but still she didn't move stuff. There'll be another nest somewhere. But I won't tell them where.... Well, I will 'cos I'm an honest dog. But why won't she move stuff? I'm a confused dog."