Florida tries to wipe out cat-sized African rats

Deep in the heart of the Florida Keys, wildlife officials are laying bait laced with poison to try to wipe out a colony of enormous African rats that could threaten crops and other animals.

U.S. federal and state officials are beginning the final phase of a two-year project to eradicate the Gambian pouched rats, which can grow to the size of a cat and began reproducing in the remote area about eight years ago.

"This is the only place in the United States where this is occurring," said Gary Witmer, a biologist with the U.S. Department of Agriculture's National Wildlife Research Center in Fort Collins, Colorado.

A former exotic pet breeder, living in a small house, bred the species and allowed the critters to escape.