'Dillos burrow and really well too. Not a trick the deer have learned yet
Yet...
Sounds to me like my varmint control (a have a heart trap) is the best way to go. Check with the local authorities, but if I can get rid of a woodchuck, you can get rid of a 'dillo...
There are sprays and some folks like castor oil, but I think those are likely hit or miss at best. Forced relocation seems the best bet. Unless you dig a fence in feet into the ground I suspect armadilloes will burrow under it...
HG