An invasive species is any species — plant, animal, or insect — that is present in an ecosystem it is not native to, and that causes, or is likely to cause, economic or environmental health or pose a risk to humans, according to the United States Department of Agriculture.
Invasive species in the US can pose a threat to native plant and animal species — including endangered species — disrupt agriculture, damage infrastructure, and pose health risks to people. Invasive species are most commonly spread by humans: for instance, one may hitch a ride on shipments across the globe.
Eradicating invasive species, like the successful efforts involving caimans in Florida, can take decades and millions of dollars.
Here are six unique invasive animal species causing environmental destruction in the US.