Invasive species are bad news. They compete with native critters for food, destroy local ecology and, in some cases, are even dangerous to humans.
And thanks to the increasingly global nature of our world, there are more and more animals discovered where they don’t belong every year.
Here are just a few pests that have hitched rides to distant shores, where they’re currently wreaking havoc.
Cane Toad
The cane toad is perhaps the most infamous invasive species. Native to Central and South America, it has been imported to a number of places — Florida, the Philippines, some Japanese islands, most islands in the Caribbean, and Hawaii, among other places — by farmers who hoped the creatures would wipe out local pests.
Instead, they got another kind of pest, one that’s much harder to get rid of. The cane toad is huge — the biggest, captured in 2007, was over 8 inches long and weighed nearly two pounds — and voracious, gobbling up many native species.
The toxins in the cane toad’s skin often kill animals that try to eat it (except for those animals who seem to deliberately get high by licking the toads), and it puts rabbits to shame with its reproductive capabilities; each female lays thousands of eggs each year.
Case in point: Australia. In 1935, 102 cane toads were introduced to combat the Greyback Cane beetle. By 2010, that number had ballooned to 1.5 billion toads spread over 386,100 square miles, and they show no signs of stopping.
The toads are hardy, too: They’ve been spotted coming out of brush fires or hopping away after being run over. One toad even survived being eaten by a dog, which threw up the perfectly-fine toad 40 minutes later.
Asian Tiger Mosquito
You’ll recognize this nasty bug, number four on the list of 100 worst invasive species, by the black and white markings on its body and legs. Native to Asia, it has spread to Europe, Africa, the Middle East and the United States — first in Hawaii in the 1800s, and then the continental U.S. in 1985, when it hitched a ride from Japan in a shipment of tires. Unlike most other mosquito species, the highly-adaptable Asian Tiger is active during the day, and lays its eggs either near stagnant water or in fresh running water.
To nourish her eggs, the female feeds off of humans, birds and other animals with a rapid bite that allows her to eat and fly before she can be swatted.
The mosquito is a carrier of West Nile virus and dengue fever, among other diseases dangerous to people. Scientists in South America are experimenting with genetically modified versions of the males — which, when released into the wild, live just long enough to mate and pass on a lab-tweaked gene that kills the larvae shortly after they hatch — though the plan to introduce those modified bugs in Key West has been met with some protest.
Burmese Python
Burmese pythons, native to Southeast Asia, came to the United States in the 1990s as part of the international pet trade. When those pets escaped their enclosures or were released into the wild, they bred, and the first established populations were reported in 2000.
These massive snakes, which grow to an average of 12 feet (although larger ones have been found, and the snakes can grow to 20 feet in captivity), are eating their way through native species throughout Florida.
Scientists believe they could eat Florida panthers, and at least one has tried to eat an alligator (albeit unsuccessfully: the snake exploded). It’s now illegal to import the snakes.
See the rest of the story at Business Insider