How did armadillos happen to be in this area?

From the text:

Before The Day he had heard someone say that there were several hundred thousand armadillos in Florida. This was strange, because before the first boom there had been no armadillos at all. Randy's father had related the story. Some real estate promoter on the East Coast had imported two from Texas for a roadside zoo. Knowing nothing of the habits of armadillos, the real estate man had penned them behind chicken wire. When darkness fell, the armadillos instantly burrowed out, and within a few years armadillos were undermining golf greens and dumping over citrus trees from St. Augustine to Palm Beach. They had spread everywhere...