Do Wombats really use their butts to fight off predators?

What exactly are Wombats? Why do they dig such amazingly long tunnels? Do Wombats actually rescue other animals during a wildfire? For free home activities sign-up at www.WhoSmarted.com See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info .