WSVN -- Some people might call them interesting looking. Other people might call them rats on steroids.
Scott Hardin: "A cat was not going to mess with a Gambian rat. No, it's too big."
But everyone agrees the Gambian rats imported from Africa are a pest.
Scott Hardin: "Nobody seems to want a whole lot of rats going around."
Yet, all of a sudden, one island in the Florida Keys was filled with the 10-pound rats after they escaped from their cages.
Scott Hardin: "It was a captive breeder on Grassy Key that had several different forms of wild life. As best we could tell, there were about eight Gambian Rats that escaped."
For a couple of years no one noticed, then the population of the big, bold rats exploded, and they started showing up all over Grassy Key.
Darla Williams: "We came home from an evening out about 9:30. They were in front of our garage door pacing back and forth. They are not like normal rats that will run from you. They are very sure of themselves."
Darla Williams is a biologist who also lives on Grassy Key, and soon many of her neighbors had Gambian rat tales to tell.
Darla Williams: "I also heard that they went to the cat door to someone's house and were eating the food in the kitchen."
With no natural predators, the population soon went from the original eight to hundreds, possibly even thousands of Gambian rats. That's when the alarm went off.
Scott Hardin: "If they leave the island and go to the mainland, you have incredible potential for agricultural damage."
Since the giant rats love vegetables, the state feared they could devastate the Miami-Dade agriculture industry if they snuck out of the Keys to South Florida.
Darla Williams: "This is an example of a bait station. There were thousands of them placed on Grassy Key."
Along with the poison, traps were set to wipe out another animal from another country in this country.
Scott Hardin: "We are approaching $300,000 for this eradication effort. That's not the end of the bill because we have to be there for at least two more years."
Patrick Fraser: "And it happens all the time, animals are flown in to South Florida by licensed breeders. They're sold as pets. They get too big. They escape, or they get thrown out, and they wind up as pests. Some are harmless, some are devastating, but all of them wind up costing you and me money."
Ron Magill: "South Florida is to animals what Ellis Island was to people. Basically, it is the port of call for every exotic animal."
Ron Magill is Miami Metro Zoo's animal guru. Ride with him, and you can see not only are foreign animals invading our neighborhoods, but they are sneaking into the Zoo.
Ron Magill: "It's a white bird with the black tail and head. That's a sacred Ibis. That's an African bird that, within the last two hurricanes have been introduced here to South Florida."
No one knows how they got here, no one knows if the new Ibis will push out the native Ibis that became UM's mascot.
But it's a different story with the invading iguana. So many have invaded the Zoo they are fighting for space.
Ron Magill: "We have actually gotten them to go out in the exhibit and take food from the animals at the exhibit, so that's how aggressive they can be."
They aren't deadly. This thing is.
Ron Magill: "See, did you see it come out that white stuff? That's pure venom."
Patrick Fraser: "What does that do?"
Ron Magill: "That will kill your dog. That right there is pure venom."
The giant marine toads were brought from Central America to combat mice. Now their poison is killing people's pets and wiping out native frogs.
Ron Magill: "These guys fit the size of a dinner plate. They eat other frogs. They eat other toads. They out-compete our native wildlife, and they are taking over that normal habitat."
Ron Magill: "This is not even full grown. These animals can exceed 20 feet."
Of course, we have all heard about the Burmese pythons slithering through the Everglades. So far they haven't been stopped, and to eliminate them will once again be costly to you and me.
Ron Magill: "When we had the Med fly invasion that cost us $50 million. The hydrilla, the plants that were in the canals that had to be taken out every month, cost us millions of dollars. Its an incredible amount of money that is costing us to try to control these invasive species."
Stopping people from bringing in these animals is a constant battle, but at least there may be one victory.
Scott Hardin: "We've done two toxic and baiting rounds. Now we think we are down to less than a dozen rats."
The state is still putting out bait and cameras to photograph the rats if they are still around, but the people who live at Grassy Key think this battle has already been won.
Darla Williams: "None has been seen, and they are pretty certain they have been eradicated."
Patrick Fraser: "Hopefully. So someone brought them here as a pet, but Gambian Rats became another costly pest for South Florida."