An Elf on the Shelf or a Mouse in the House?

There's a Mouse in the House, this is well known, but strange things can happen and it seems it is true.

That this mouse in the house has become a spy you may see, 

to keep a close eye on you and perhaps even me.

To report back to Santa on who has been good, he'll write in his book those naughty and nice (and it won't be the mice!)

That Mouse in the House may not need to look twice.

So best to behave, not leave it to chance.  

For that Mouse in the House is a crafty wee fellow who can creep around corners, while we are quite unaware...and make his decision with just the one glance.