Deer Mouse Scat and Tracks: How to Identify Them (Peromyscus maniculatus)

Rodent droppings are small and dark; shape and size are the first cut (rice-grain with pointed ends for mice, blunt and larger for rats, oval pellets for squirrels and voles). Tracks show four toes on the front foot and five on the hind, and most rodents bound, so the larger hind prints land ahead of the front prints. Gnaw marks with paired incisor grooves are often the clearest sign. The measurements below for Deer Mouse are quoted from the wildlife agencies linked at the bottom of the page.

• Size: About 0.25 inches long
• Shape: Slender, tapered at both ends

• Nests underground or in a concealed spot: Deer Mice often build multiple nests in underground burrows among tree roots, under logs or boards, or in tunnels abandoned by other animals; a few nest in fence posts, stumps, logs, or old bird/squirrel nests
• Gnawed packaging/containers, dragged-off nesting material: Signs of mice (including Deer Mice) include droppings, gnawed-through bags and containers, and nesting material carried off

The White-footed Mouse has the same coat color as the Deer Mouse, making them hard to tell apart by appearance

Human contact with the urine, droppings, and saliva of mice (including Deer Mice) can spread hantavirus If you need to clean it up, wear gloves and a mask, wet it down first, and bag it; see the CDC guidance linked in the sources.

Put something of known size next to it (a coin, a pen, a boot) and shoot straight down in soft light; low side light brings out the shape of tracks in mud or snow. For scat, photograph the whole deposit and one close-up showing contents. Note where it was: on a log, in the open, on a trail, near water. The app suggests the likely animal; confirm with the size and shape notes above.