Monique van Someren/Getty Images; Picture by Tambako the Jaguar/Getty Images; Craig Cordier/Getty Images
- Invasive animals threaten native species, damage agricultural crops, and pose health risks to humans.
- Some of the odder invasive species include hammerhead worms and giant snails.
- Here are six uniques species causing problems in the US.
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.