Some interesting facts about armadillos that I've learned:
1) Armadillos are mammals, in the same family as anteaters and sloths. They originated in South America.
2) There are actually 20 different species of armadillos, but only one species (the nine-banded armadillo) currently lives in the U.S.
3) Most species of armadillos are threatened or endangered. Currently only the nine-banded armadillo is actually increasing its numbers and range.
4) Nine-banded armadillos always give birth to four identical young (called pups or kits) - which develop from the same egg and share the same placenta. The female armadillos have only 4 mammary glands, one for each pup.
5) Nine-banded armadillos eat primarily small insects, which they slurp up with their long, sticky, saliva-covered tongue. Ants and beetles (including grubs) are their favorites. If pressed due to lack of insects, they will also eat plant material, carrion, and even occasional small mammals, eggs, and/or nestling birds.
6) Prior to about 1850, armadillos were not found north of the Rio Grande. Their range has currently expanded north to Nebraska & Missouri and east to Florida & South Carolina. This range expansion is occurring almost ten times faster than would normally be expected for a mammal species.
7) If startled, an armadillo will often jump 3-4 feet straight up into the air. While this is great for startling its predators, it usually proves to be a fatal response to an oncoming car.
8) The word "armadillo" means "little armored one" in Spanish.
9) Nine-banded armadillos cannot roll up into a tight ball. They usually run to a nearby burrow, dig into the ground or hunker down tight against the ground when faced with a predator. (Except, of course, when they jump straight up into the air - see #7 above.)
10) Armadillos are considered an important part of ecosystems because of their insect-eating (and therefore insect-controlling) habits. If you can stand their hole-digging habits in your yard, there is benefit to be gained by their appetite since they are excellent grub control.
Unfortunately, I'm having real issues with their hole-digging habits....
Sources of information: