#mouse work

Via Metafilter:

Someone on MeFi tagged me in and asked me to chime in in my capacity as a rodent person, so here were my thoughts and observations:

First thought, looking at that video: that is no house mouse. Not only is the head wrong--too narrow at the back, eyes are a bit big--but that very clear countershading is not something you generally see on wild house mice. So what kind of mouse is it? If this was in the US, I would assume it was a Peromyscus (deer mouse) species, which often gleefully invade our homes, but do they have Peromyscus in Wales? In North America, this is relevant because deer mouse species often have very elaborated burrowing and pair bonding systems, and this looks like nesting behavior off the top of my head. What sort of mouse is this? The Woodland UK Trust suggests that this is probably a wood (or field) mouse: Apodemus sylvaticus. (There are glorious big photos there which can help you see what I mean.) Okay, I don't know that much about Apodemus spp. behavior, so what do we know about their nesting behavior? Well, I chased a couple of false leads, then circled back to find out what is notable about wood mice, which is that they are known to not only navigate by the use of landmarks, but to organize their environments to place small objects around their environments in order to make navigation and orienting themselves across their large territories more effectively! So this mouse is probably irritably putting things back in place as an aid to its own memory of where everything is and where it can most effectively pilfer snacks, nest locations, or other useful mouse items within its environment. That is, the mouse wants a tidy shed for exactly the same reasons a human might want a tidy shed: so it can find things it's looking for when it wants to! Wood mice, by the way, are human commensals and quite common in Europe and the British Isles, so this is in no way a refutation of the idea that this behavior might have influenced human folklore and ideas about house spirits or similar. Certainly wood mice, like any mouse, are unlikely to turn up a bowl of milk if there's one put out for it--although neither are house cats, which would certainly prey on them.