Shooting Armadillos

Ok guys, Ive not seen any info on Armadillos on this forum. Im in southern Illinois and I now have an infestation of the critters and they are burrowing around the foundation of my house. Im shooting a .25 Bobcat. Any info about how effective that caliber is against their armor for a heart lung shot or should i go for a head shot. I don't want to trap them or poison them. Would rather leave them for the coyotes. Also are they protected in Illinois?
 
When my neighbor’s lawn was assaulted by an armadillo, he came to me and asked if I could solve the problem with my air rifle. Two months later the opportunity presented itself and I dispatched the armadillo with a head shot at just under 20yds. I used my .22 Air Arms TX200 with the H&N 12.65gr Baracuda Green pellet. It was 10pm in Lexington, TN and the armadillo was walking along the wood-line behind the garage. I heard the shot impact and the armadillos' head went back. He froze and then shook his head before he walked about 10-12 feet and fell over dead. 
 
There is more than enough power for a heart and lung shot 50 yrd and under. I just laugh to myself when I hear people talking about the effect their armour has on bullets. It's basically fish scale wrapped over a 1/4 inch of hide. I think it actually becomes harder after the animal has been dead for a month or so, but anyways I used to have a real infestation of them and remedied it with my wildcat 25. Just remember good shot placement, and they can't see worth a crap.