Plants and animals adapt over the centuries to the habitats and conditions where they originate. And for just as long, humankind has been moving those organisms to new homes - sometimes intentionally, sometimes not. Not all introduced species are invasive. Some - certain species of trout and bass in the Pacific northwest, for instance - have become important sport or economic resources. But when an introduced species is bigger, tougher, hungrier or faster-growing than others in its new home, it can crowd them out and wreak havoc on entire ecosystems.
Learn more about our invasive species programs and what we can do to help.