I'm sure I just saw the White Rabbit go down this hole. (Rabbits in Australia can be a really big problem on pasture land as they can ruin it with their enormous warrens.) They are not the sweet little bunnies you see in other parts of the world.
They must be like our pesky raccoons or armadillos. Clever title and who knows what you'll find if you decide to crawl through that hole and take a peek ;-)