Mystery mouse

Here's one of the clean-up squad who benefits from the seeds flung out from the feeders by the coal tits and other untidy eaters.  The little field mice are welcome, their bigger cousins are not, though we haven't seen one of them around for quite a while.

We had a mysterious incident a few months ago, shortly after I began making our sourdough bread.  I left the dough out overnight for a slow rise, and covered it with the linen liner that comes with the proving basket.  In the morning, the linen cover had a few ragged holes, but the dough underneath was beautifully domed and intact.  There was no sign of the culprit, and I did have this slight irrational concern that a mouse had actually got into the basket and been swallowed up by the expanding sourdough.  And with each slice we took of the resultant bread, I wondered whether the endoughed mouse would be revealed in section. It wasn't of course. 

There was no sign anywhere else of a mouse's activities, and we have never previously had a mouse in the kitchen. No further sign was seen until earlier this week when I found a hole had been chewed in one of the bird food bags. That must have happened recently or else I surely would have noticed it before when I was filling the feeders.

We do hear mice in the attic above our bedroom, but there is no cavity wall for them to move downstairs and through to the kitchen and its next door Utility Room.  I have tried unsuccessfully for weeks to catch the mouse or mice in the loft using a non-lethal tippy trap baited with chocolate, but no success.  Where will Mystery Mouse strike next?

ps A nice coincidence that the little mouse thumbnail was uploaded next to a blip by Rat.