Several giant Gambian pouch rats have been found recently on Florida's Grassy Key despite concerted efforts by conservation officials to eradicate them.

Officials worry that the voracious rats, which grow to nine pounds, might wipe out some crops and upset the delicate ecological balance if they manage to reach the Florida mainland.

South Florida has become a virtual dumping ground for exotic animals from across the globe.

The area is teeming with exotic animals like Burmese pythons, boa constrictors, Nile monitor lizards, vervet monkeys and more--all wreaking havoc on local animal species.

The Gambian rat first appeared on Grassy Key in 1999 after eight rats escaped from a local exotic pets breeder.

'We thought we had them whipped as of 2009,' Scott Hardin, exotic-species coordinator for the Fish and Wildlife Conservation Commission, told keysnet.com.

'In the early part of 2011, a resident e-mailed me and said he saw one of the rats. We were skeptical but went back and talked to people and [saw] there were rats that we missed,' he added.

After four female rats were found in 2011, officials launched another effort to kill them in November and December, primarily through the use of poison-laced cantaloupe and peanut butter. Read More

Reintroducing predators such as dingoes and tasmanian devils into landscapes may help protect Australia's diminishing biodiversity, researchers say.

A new paper to be published in the May edition of Trends in Ecology and Evolution suggests dingoes and tasmanian devils could control invasive species, such as cats and foxes, as well as overabundant herbivores.

"We need to be quite bold and allow predators back into the landscape and see if they can reverse some of the damage we've done," said Dr Euan Ritchie, ecologist at Deakin University in Melbourne and lead author of the paper.

Since European settlement, humans have drastically altered the Australian environment, resulting in one of the highest rates of species loss in the world.

Cats and foxes have wreaked havoc on small wildlife species, while larger natives, such as kangaroos, have multiplied. Read More