Peppermint oil spray makes a good repellant for rodents. You can buy it online or get a recipe for making your own. The commercial versions usually have other essential oils mixed in that make them more potent. Just a thought.
BTW, armadillos are usually hunting for earthworms. They have a great sense of smell so anything that interfere with that will usually drive them away. Garlic, ammonia, peppermint, etc will usually deter them from hunting in your yard.