Oh man, armadillos are pesky. A couple of years ago we had one that somehow got into our backyard. I chased him around the yard and he eventually burrowed under some bricks/rocks by our fence and wouldn't budge.

I Googled how to repel them and they said they have a strong sense of smell, so use vinegar or amonia around the yard. I went under our sink and grabbed a gallon of apple cider vinegar, walked out to the armadillo and poured it directly on top! Hahah. Needless to say the armadillo found its way out of the yard VERY quickly :D