I saw some armadillos in the yard the other day. I read up about them and realized they are mammals and have a leathery armor shell.
That's so cool!  Do they just run wild like that?
They do. They are native to the Americas. They inhabit all types of different terrains and environments.
Wow, you're so lucky!  All I get in my yard is rabbits, and they eat my garden vegetables!  Were you able to get up close to it?
Funny you should mention rabbits. The Aztecs had a word for armadillo that pretty much translates to "turtle-rabbit". 
LOL!  That's so funny!  I bet that hard shell protects them quite a bit from other animals?
That would be correct. Some have different number of bands on their shell. This is how you can tell which species of armadillo they are. There are about 21 different species.
What do they like to eat?  Not garden vegetables, I hope!