What is an invasive species?

Water hyacinth (Eichhornia crassipes) David Sanger / Getty Images

Invasive species can mean a lot of things, from fungus to feral pigs and European starlings to kudzu vines. Basically, it's anything brought to a place, either by humans or nature, that didn't originate there. They aren't always a problem, but many times they can wreak havoc on the local ecosystem. Learn all about these invaders today.

If you dig the topic, read "How Invasive Species Work."

Topics in this Podcast: bacteria, plants, insects, animals, science, biology