Image 5Pacing diagram for Virginia opossum - key: rectangles represent hind tracks, ellipses are fore tracks, left tracks are red, right are green. (a) the position of the four feet frozen in mid-pace. (b) the opossum brings right fore and hind feet forward. (c) the opossum brings left fore and hind feet forward. One grid square represents one square inch. (from Virginia opossum)
Image 6The back foot has an opposable "thumb". (from Virginia opossum)
Image 7Opossum tracks (photo center) in mud: Left-fore print appears on left center of photo, right-hind print appears right center. The small, circular tracks at bottom center of photo were made by a meadow vole. The yellow ruler (top) is in inches.
Image 8When injured or threatened (e.g., by a dog), the Virginia opossum is known to feign death or "play possum".