Rodent

Recently we've had a better look at our rodent friend, who appears to enjoy lemons. A couple of weeks ago we heard him munching downed lemons outside our bedroom window. The other day Andrew caught him mid-stride in our driveway. Definitely not a rat. But definitely some sort of rodent. Quite large. We're thinking maybe a possum? But don't know much about them things. Anybody out there have ideas?