I don't think you have to worry about armadillos. They are pretty benign as far as critters go. Possibly they might dig under the coop, but I don't think they'd harm anything, even chicks or eggs. Dillos are insectivores.
There was one in my yard the other day drinking out of a pan of water. I'm going to try and keep it full for him, so he'll stay out of my pool.
No armadillos eat insects and soft grubs and worms. They won't bother your chickens except to maybe dig a hole under their fence. They can make alot of ankle killer holes in your yard though. I remember one summer we had one to dig a den under a big bush in our front yard. The dogs would have a fit every night when she came out to dig up our yard. One really hot day when we were in the middle of watermelon season and had our signs up to sell melons, this old pickup drove up. An elderly lady got out and walked up to our front porch. She asked in a real mountain folk, true southerner voice "Are you folks a-raisen arm-a-dillas here"? That mama armadillo and her four little ones were right out in the middle of our yard. My nieces, nephews, and brother had to chase them all over the yard before catching three of them in 5 gallon buckets. We took them far away before turning them loose.