Moving using saltation, which animal cannot walk backwards?

Never heard of saltation before! There are so many kangaroos around our town at the moment that most of us have dints in our car bonnets, and smashed headlights. It’s a horrible experience to hit a roo: around dawn and dusk, they will just suddenly bound onto the road in front of you. I hit one last week which had to be shot by Wildlife Rescue. Heartbreaking. (Plus very expensive repairs to my car!)