The mouse opossum is, in fact, the size of a mouse. But it isn’t a rodent at all. It’s a marsupial, and more closely related to a kangaroo than a rat. There are 55 different species of mouse opossum in Central and South America and they are all nocturnal. I came across this one well after dark while camping in the Pampas region of Bolivia.
Nikon D300 with Nikkor 200-400mm lens (at 260mm) ISO 200, f/6.3 at 1/60th of a second, two Nikon SB-800 flash units