Gray squirrels are known for their bushy tails and hoarding habits. These North American natives were imported to parts of Europe and South Africa as pets, but quickly went from pets to unwanted pests. Learn more about the problems caused by invasive gray squirrels and what can be done to solve them.
American mink have beautiful, thick, glossy fur. At one time, many were exported to other countries where farmers raised them for their fur. Find out what happened to native species when fur went out of fashion and many minks were released into the wild.
Asian carp have big appetites and can leap out of the water when startled. They were brought to the United States from their native Asian habitats to control algae growth on fish farms. Find out what happened when some of these big, jumping fish escaped and made their way up the Mississippi River.
Cane toads are known for their warty skin and poison glands. They were brought to Australia and other places to help control pests that were harming crops. Learn more about how the cane toad has gone from being farmer's friend to an unwanted pest.
Emerald Ash Borers have shiny green bodies and an appetite for ash trees. This native Asian insect hitchhiked to North America and has killed millions of ash trees. Learn more about the emerald ash borer and what is being done to try to stop its spread.
Starlings have glossy feathers and are aggressive competitors for nesting sites. Native to Europe and Asia, these birds were introduced to North America, Australia, and South Africa. Find out why these feathered invaders pose a threat to native birds species and farm crops.
Zebra Mussels are known for their striped shells and clingy habits. These natives of Europe and Asia traveled to North America in by ship. Learn more about why the zebra mussel poses a threat to native animals and the health of North American waterways.