Armadillo Repellent
While you're at the home supply store make sure you pick up some toilet motors along with your armadillo repellent. You'll also need some fence grease and a bucket for your floodlights. I'm joking. However, the armadillo repellent is an actual product you can buy. Several big name brands endorse this product and a search for how to get rid of armadillos yields shopping results for all manner of chemical and audio armadillo repellents.
Chemical Repellents for Armadillos
They come in liquid and granule form, and sometimes pellets. They are not proven to work and all options I just listed can easily be washed away with rain, carried off or mistakenly eaten by household pets, or soakl into ground with zero effect. My best advice? Save your money and buy a trap if you're going to do this for yourself instead of hiring a pro. While professional services can cost money but will be done right, or a trap can become a home DIY investment, your money is going straight down the toilet when you buy these phony repellents.
Noise Makers for Armadillo Removal
I've seen a motion activated floodlight and high frequency noise generator recently going for around $100 that's supposed to scare away the animals in your yard at night. The light itself does all the work, the noise generator is just for show and to make you think it's more effective than a $20 motion-activated floodlight. You really should have a motion-activated light anyway as part of a solid home security plan. Anyway, the noise makers don't work on any animal. Animals are like humans who will run away from loud or obnoxious noises, anyway. They jsut hide. They may not be able to process the concept that the noise only exists in the area that they are currently in.
Alternatives to Phony Repellents
If you find yourself having spent a decent amount of money on repellents, at least try to get your money back from the manufacturer or the store. After you've done that, you can go the route of removing the armadillos yourself, or take to the yellow pages and find a local trapper. Our local directory lists tons of local trappers across the United States so feel free to use that while you're here.