Nile crocodiles have been discovered living in Florida swamps, the latest in a line of exotic and often dangerous foreign species living in the southeastern US state.

Florida's hot, humid climate is an ideal home for all kinds of illegal reptiles, including giant Burmese pythons, Nile monitor lizards and Madagascar geckos. Most were likely released by private exotic animal collectors.

University of Florida experts have now confirmed the discovery of two and possibly three Nile crocodiles, animals that -- unlike the local alligators -- can prey on humans.

Over the last decade several large groups of Nile crocs "have been imported from South Africa and Madagascar for both zoological display ... and the pet trade," read an article in the academic journal Herpetological Conservation and Biology.

Nile crocodiles, which can grow up to six meters (20 feet) long, are known to prey upon creatures such as shrimp, fish, insects, birds, and mammals including humans, the herpetologists wrote.

For comparison, American alligators -- common in south Florida and Louisiana -- grow to about four meters long.

As for the less common American crocodile, a threatened species that is "shy and reclusive," there are only extremely rare reports of conflicts with people, according to a Florida Fish and Wildlife brochure.

The Nile crocs can feel entirely at home in Florida and much of the Gulf of Mexico, where the weather and flora is similar to that of its African habitat.