Here is everyhting you could wnat to know about armadillos
Nine-banded Armadillo - Wikipedia, the free encyclopedia
They are not particulalry agile, so if your property is fenced (with a fence they can't dig under) they aren't much of a nuisance. I'm not aware of any repellants for them, but you may try Irish Spring soap, works for me to keep deer off things (they can't stand the smell). Just make flakes of the bar with a pocket knife and spread the flakes around what you don't want chewed up.
