Top 10 Weirdest Invasive Species In Florida


The Florida Everglades have gained a lot of notoriety over the years as an escaped exotic pet haven, as illustrated by problems like the massive Burmese Python. Unfortunately for Florida residents, giant snakes aren’t the only foreign creatures being set loose around their fair state, and many are even more dangerous. Such as …

10. Lionfish

Image result for Lionfish

Certainly one of the oddest-looking invasive species closing in on Florida’s shores is the lionfish, a magnificently-colored, predatory reef fish adorned with intricate stripes and venomous barbs at the end of its long, fanlike fins. When a few of them were dumped by their owners in the 1980’s, they weren’t thought much of; however, since 2000, they have been establishing a startling presence across the entire Caribbean.

Since colonizing the area, they’ve been terrorizing the ecosystem — lionfish feed primarily (and voraciously) on small herbivorous fish (slashing their survival chances by 80%) and researchers fear that, without them, seaweed will overwhelm many reefs. The recent spread of lionfish leads researchers to believe that these brilliant exotic fish could truly decimate the local ecosystem.

9. Tegu

Argentine Black and White Tegu-Tupinambis merianae

The tegu is a hefty, 4-foot long lizard from South America. Its docile nature makes it a popular species for exotic pet buffs in Florida, but don’t be fooled: tegus are known for their insatiable omnivorous appetite. In Brazil, they’re used to control rat populations, and sport some large, nasty claws to help do the job. When one of the monstrous lizards was spotted in Ocala National Forest, an obvious concern arose for native species in the area.

The tegu’s penchant for native gopher-tortoise eggs is particularly worrisome, since the already-threatened species faces other obstacles like construction bulldozers. Only a handful of tegus have been spotted in the wild, and usually in heavily frequented nature preserves. However, their popularity, combined with Florida’s notorious habit of releasing their pets, means they could become a very real threat in the near future.

8. Cuban Tree Frog

Image result for Cuban Tree Frog

First introduced to Florida by riding on shipping containers from the Caribbean, the Cuban tree frog is becoming a veteran invader. By the 1970’s, it had already begun establishing itself across southern Florida and, as of 2010, there appear to be healthy breeding populations as far north as Gainsville.

Despite their small size (large females only reach about 6 inches,) they’re outdoing Florida’s two native species of tree frog, and even eating them directly. They also thrive in residential areas, invading homes in search of shade during the day. At night, it’s not uncommon to see them hanging from windows and walls snagging insects … and defecating everywhere, including those same windows and walls. The frogs can also be found in the toilet, where they usually end up after sneaking in through a house’s ventilation or plumbing systems.

To top it off, they have unbelievably loud and obnoxious calls, and their skin secretes a toxic mucus that can be very irritating to the eyes and nose. So, while not necessarily a huge environmental threat, Cuban tree frogs are an enormous nuisance just about everywhere it goes.

7. Walking Catfish

Image result for Walking Catfish

Some fish swim; others, like the walking catfish, prefer to (you guessed it!) walk. It’s native to southeast Asia, but established a presence in Florida in the 1970’s, after being released into the Everglades. Since then, it’s been moving north via canals and sewer systems. And occasionally, there are some absolutely bizarre sightings, such as residents walking outside and seeing catfish on the streets, just walking around and enjoying the day. If a school of catfish wandering around on the street after a stormy night isn’t unnerving, we’re not sure what is.

6. Nile Monitor

Native to Africa, Nile monitors can grow larger than the Komodo dragon. Unsurprisingly, they hold a powerful allure with Florida’s exotic pet fanatics, but their immense size means they’re incredibly hard to care for. They are notoriously ill-tempered animals and aren’t afraid to mess with people, even entering homes through doggie doors. To match their bad attitude, they’ve got a mouth full of sharp teeth, large claws, and a massive tail that they use like a whip.

The giant lizards are obviously perceived as a threat to families with small children and pets, and with good reason: Nile monitors can reach 10 feet long and sport an appetite for just about anything, flora and fauna alike. Apart from their ability to run near 20 mph on land, they’re also powerful swimmers that can remain submerged for an hour at a time, making it very hard to contain their spread through Florida’s sprawling canal system. Nile monitors are thriving in the humid conditions of Florida — the hotter and wetter, the better — and it’s safe to say that, without a new plan of action, they’re not going anywhere.

5. Cane Toad

Cane toads are enormous, ugly, and poisonous. Their introduction into Florida is the product of a 1955 pet vender malfunction, in which 100 of them were released into a Miami airport. Subsequent releases over the next few decades gave them a good jumping off point to spread all over Florida, and that’s exactly what they’re doing. They are very predatory, feeding on all types of native frogs and toads, and even eating pet food.

And, as if to add insult to injury, their toxic secretions have been known to kill household pets, if ingested. And if it isn’t fatal, the toxin causes a clinical condition called Giant Toad Poisoning; symptoms include drooling, crying, coordination loss, and even convulsions. The major threat that cane toads pose to their new home is that, aside from eating everything they can fit in their mouth, they can severely damage or kill anything that tries to eat them. Since native Florida predators aren’t adapted to its potent toxins, they have little resistance to the toad’s chemical defense.

4. Spectacled Caiman

Image result for spectacled caiman

Florida’s reigning top crocodilian predator is the American alligator, which reaches 15-20 feet long. A new invader is arriving on the scene, though: the spectacled caiman. Caimans, endemic to South and Central America, aren’t nearly as large as their North American counterparts, only reaching about 6 feet long. However, they’re very efficient breeders, and can establish a population quickly. Their ability to tolerate both salt water and fresh water makes them able to thrive in all kinds of marine and wetland areas, especially in the rich Florida Everglades, where they were released in the 1960’s.

Actively breeding species have been found breeding as far north as Palm Beach. The spectacled caiman’s diet can accommodate just about anything, and their appetite is just as enthusiastic, making them problematic for native vertebrate and fish populations.

3. Wild Hogs

Image result for wild hogs

Wild pigs are the single most destructive invasive animal species in America, costing millions in property damage yearly. They aren’t confined to the farmlands of the South as previously thought, either — they’re terrorizing urban Florida neighborhoods, digging up gardens, lawns, and the like at night in search of food. The destruction they cause has been sufficient enough to get the federal government involved, conducting dog hunts and providing cash rewards for killed pigs. Taking on these horrifying hogs is by no means an easy task, seeing as they do most of their work at night. On top of that, they can grow to be 300 pounds, and frequently outsmart trappers and hunters alike.

2. African Rock Python

Image result for African Rock Python

The already-exploding population of burmese pythons in Florida has led to an infestation of the Everglades, and the death of thousands of native animal. However, they might not even be the biggest issue on the agenda. African rock pythons are the largest snakes in Africa, reaching 20 feet in length. They feed on animals the size of antelope, and sometimes even crocodiles.

And yes, they’re in Florida now. Multiple specimens, including a pregnant female and two young hatchlings, indicate that the pythons not only been breeding, but they’re settling in for the long haul. Pythons are known for their admirable ambition when it comes to eating animals the size of themselves, and African rock pythons are no exception. Florida scientists think that the pythons will eat just about anything warm-blooded, provided that it can fit in its mouth … meaning, it’s not so hard to imagine a 20-foot constrictor preying on alligators, deer, household pets, and maybe even children.

1. Feral Cats

Feral Cat

That’s right; one of the most destructive forces on Florida soil is the feral cat. It’s estimated that 60-100 million rogue house cats may be terrorizing the wild, having numerous negative effects on the native biology. Because they aren’t a natural part of the ecosystem, they’re easily able to predate unwitting birds –perhaps as many as 8 million a year, with a single cat able to take down 100 in a year. They also compete with native predators and spread diseases, while preying on bird feeders for food, and even defecating in residents’ gardens.

While these felines might not seem like an “invasive” species at first glace, they certainly aren’t native; even domesticated cats were originally native to areas like Egypt, and were never meant to be incorporated into Florida’s ecosystem. Many are tempted to try and re-domesticate escaped kitties, to try and spare the local birds and rodents. However, as any cat owner will tell you, they will hunt and kill mice and birds even if they’re well-fed. It’s just what cat’s do.

Written By Cameron Kesel

Other Articles you Might Like
Liked it? Take a second to support on Patreon!


  1. Where I dive in Florida we see lion fish once in a while. I don’t have the gear to kill one but they don’t move often so we inform the local dive shops and within a day or two they’re killed by somebody.

  2. #8 Frog looks really happy, but #5 Frog looks like an unhappy politician who’s just about to launch his losing campaign for the office. Whazzup? 😀