I am not sure that armadillo's fart CO₂ (carbon dioxide), I may be wrong, but like most critters they fart hydrogen sulfide (CH₄). That is a little different from CO₂.

CO₂ is good and essential for plants to live. CH₄? It stinks (hell it is a fart), and is pretty flammable.

Am I a chemist? No, just used to light my farts when I was in the Corps for laughs. I also fart CH₄ more so now that I am up in age. Lots of fiber in my diet.