Top 10 Invasive Species

September 3, 2014 3:11 PM EDT

This is the camel cricket. You hate it, don’t you? You should. Let’s start with the fact that it’s—how to put this nicely?—repulsive. Add the fact that it’s big, by bug standards at least, measuring up to two inches (5 cm) long; that it resembles a spider more than a cricket; and that it will eat nearly anything—including other camel crickets, which is just plain bad form.

Now to all that, add the additional fact that camel crickets are here. And by “here,” we mean everywhere. An Asian species originally, it has now turned up in more than 90% of cricket sightings across the U.S. It wasn’t as if we needed the import, thank you very much. The North American continent already had its own species of camel cricket. But the Asian variety arrived and appears to be crowding out the native species. There are, at current estimates, more than twice as many camel crickets of all species in America as there are actual Americans, with the bugs outnumbering us 700 million to 314 million.

In fairness, camel crickets don’t bite or pose any other particular threat to people. And since they’re scavengers, they also help keep ecosystems in balance. So really, we should be glad to have them–even welcome them, right? Nah. Sorry science, this time we’re going with our guts: camel cricket, here’s your tiny hat. Please go home.

Greenhouse Camel Cricket (Diestrammena asynamora), Woburn, Massachusetts — A Camel Cricket in Massachusetts on Nov. 18 2011. Piotr Naskrecki—Corbis

In the 1970s, catfish farmers used these hardy foreign carp to remove algae from their ponds. But over the decades, floods that caused catfish ponds to overflow have released the species into the Mississippi river basin. Asian carp can grow to 4 ft. (1.2 m) in length and weigh over 100 lb. (45 kg), and have a tendency to leap out of the water, injuring fishermen and the occasional newscaster. With no natural predators and a predilection for killing off other marine life by eating all the plankton, the carp have overrun the Mississippi and are swimming towards the Great Lakes, the world's largest freshwater ecosystem. — In the 1970s, catfish farmers used these hardy foreign carp to remove algae from their ponds. But over the decades, floods that caused catfish ponds to overflow have released the species into the Mississippi river basin. Asian carp can grow to 4 ft. (1.2 m) in length and weigh over 100 lb. John Flesher—AP

Robben Island, the tiny piece of land just off South Africa's southwestern coast is overrun with rabbits. A New York Times report revealed that up until October 2009, rabbits — probably brought to the island 300 years ago by Dutch explorers — have lived there unchecked, burrowing holes under buildings and depleting grassy areas. So far, 5,300 rabbits have been killed and estimated 8,000 more will need to be exterminated. — Robben Island off South Africa's coast, where Nelson Mandela was imprisoned for 27 years, is now overrun with rabbits. A New York Times report revealed that up until October 2009, rabbits — probably brought to the island 300 years ago by the Dutch — have lived there unchecked, burrowing holes under grassy areas. Robin Hamin—The New York Times/Redux

Originally introduced to control pests, the cane toad has become a pest of its own. Native to Central America, the toads were brought to Australia in 1935 in an attempt to control the cane beetle population in sugar plantations. Ultimately there was no evidence they killed a single beetle. Instead, the toads took over. Cane toads have few natural enemies outside of Central America, and when other animals try to eat them, sacs that run down their sides secrete a poison that kills predators in minutes. — Originally introduced to control pests, the cane toad has become a pest of its own. Native to Central America, the toads were brought to Australia in 1935 in an attempt to control the cane beetle population in sugar plantations. Ultimately there was no evidence they killed a single beetle. Instead, the toads took over. Ian Waldie—Getty Images

Some call it "the vine that ate the South." It grows up to 1 ft. (30 cm) every day in the summer months, and can break power lines, kill trees and collapse buildings. Used for decorative and medicinal purposes in Asia, kudzu was first seen in the U.S. when the Japanese made it part of a garden at the Centennial Exposition in Philadelphia in 1876. Americans fell in love with the vine's bright green leaves and fragrant flowers; in the 1930s, the government paid farmers to plant it to prevent soil erosion. But kudzu grew too well outside its natural habitat; it thrives in the hot summers and mild winters of the southern states, is difficult to uproot and has no natural predators outside of Asia. — Some call it "the vine that ate the South." It grows up to 1 ft. every day in the summer, and can break power lines, kill trees and collapse buildings. Used for decorative and medicinal purposes in Asia, kudzu was first seen in the U.S. when the Japanese made it part of a garden at the Centennial Exposition in Philadelphia in 1876. Melissa Farlow—National Geographic/Getty Images Images

You wouldn't guess to look at it, but the deceptively adorable gray squirrel could be the most loathed animal in Britain. Grays, which are native to North America, carry deadly squirrel pox, to which they are immune but native red squirrels are vulnerable. They also eat seven times more food per hectare than their scarlet cousins, crowding out any competitors who manage to survive the squirrel plague. — The deceptively adorable gray squirrel could be the most loathed animal in Britain. Grays, which are native to North America, carry deadly squirrel pox, to which they are immune but native red squirrels are vulnerable. They also eat seven times more food per hectare than their scarlet cousins.Marc Rasmus—Getty Images

In 1957, a beekeeper in São Paulo, Brazil, accidentally released 26 Tanzanian queen bees who went on to launch an agricultural calamity, a horror-movie franchise and a whole new level of melissophobia. The queens mated with native European honeybees to create so-called killer bees, or Africanized bees — an especially aggressive species. Africanized honeybee swarms have been known to stage coups where they invade European honey hives, kill the European queen and install their own leader. The bees first infiltrated the U.S. in 1990 and have since spread to the southern parts of many states, including California, Nevada, Utah, Arizona, New Mexico, Texas, Oklahoma, Louisiana, Arkansas and Florida. — In 1957, a beekeeper in São Paulo, Brazil, accidentally released 26 Tanzanian queen bees who went on to launch an agricultural calamity, a horror-movie franchise and a whole new level of melissophobia. The queens mated with native European honeybees to create so-called killer bees, or Africanized bees.Kevin Schafer—Corbis

In 1890 New York drug manufacturer Eugene Schieffelin released some 60 European starlings in Central Park. His dream was to introduce every bird mentioned by Shakespeare into North America — an intent that proved to be more Hitchcock than Bard. Schieffelin hoped the songbirds would prosper in their new home in ways the skylarks and song thrushes had not, and they certainly did. Now the purple-green iridescent birds roost in hordes of up to 1 million; they can devour up to 20 tons of potatoes in one day and their droppings are believed to be vectors of several infectious diseases. — In 1890, New York drug manufacturer Eugene Schieffelin released some 60 European starlings in Central Park. Now the purple-green birds roost in hordes of up to 1 million; they can devour up to 20 tons of potatoes in one day and their droppings are believed to be vectors of several infectious diseases. Menahem Kahana—AFP/Getty Images

The northern snakehead fish has teeth like a shark and the ability to walk on land. The carnivorous fish hails from Asia but in 2002 it appeared in a small Maryland town, where it promptly obliterated wildlife in the local pond. While other invasive fish species can only travel as far as the waterways will take them, the snakehead, sometimes called "Fishzilla," can survive for up to four days out of the water and travels across land by wiggling its body back and forth like a snake. The fish has since been spotted everywhere from New York to California. — The northern snakehead fish has teeth like a shark and the ability to walk on land. The carnivorous fish hails from Asia but in 2002 it appeared in a small Maryland town, where it promptly obliterated wildlife in the local pond. "Fishzilla" has been spotted everywhere from New York to California. Kim Hairston—Baltimore Sun/Getty Images

Though mussels are considered one of the great delicacies of the seafood world, a particular variety of the crustacean has left a bitter ecological aftertaste. Zebra mussels, an invasive species native to the Caspian Sea are thought to have hitched a ride to the midwestern Great Lakes in the late 1980s by clinging to the hulls of U.S.–bound European vessels. The unwelcome visitors, that have since spread east to New England, are known to feed on the phytoplankton that nourishes the filter feeders which support the diets of larger fish— effectively starving other species unfortunate enough to live alongside them. — Zebra mussels, an invasive species native to the Caspian Sea, are thought to have hitched a ride to the midwestern Great Lakes in the late 1980s by clinging to the hulls of U.S.–bound European vessels. The unwelcome visitors, which have since spread east to New England, are known to feed on the phytoplankton.Visuals Unlimited/Corbis

The snake craze that caught on among American pet owners in the mid-1990s grew out of control — literally — when python owners began releasing the 20-ft. (6 m) creatures into the wild once they became too big for their tanks. Unlike many domesticated animals who can't survive in the wild, the pythons have thrived and multiplied, particularly in the Everglades where they have become a scary nuisance, posing a potential threat to humans and feeding on native endangered species such as Key Largo wood rats, round-tailed muskrats and even alligators. — The snake craze among American pet owners in the mid-1990s grew out of control when python owners began releasing the 20-ft. creatures into the wild once they became too big for their tanks. Unlike many domesticated animals who can't survive in the wild, the pythons have thrived and multiplied, particularly in the Everglades.Wayne Lynch—All Canada Photos/Getty Images

The Asian Camel Cricket and 10 Other Invasive Species You Might Not Know

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