From cane toads to kudzu, invasive species (sometimes called alien species) are those that aren't native to an ecosystem and that cause harm to native species, local economies or humans. Invasive species can be terrestrial species, like the pythons invading Florida's Everglades, marine, like the lionfish invading Caribbean waters, or pathogens. Invasive species can cause harm by out-competing native species, or preying on them. They can sometimes increase fire risks or contribute to erosion. Some invasive species have been introduced accidentally and others, like kudzu, were introduced on purpose and then spread more widely than originally intended. Invasive species are found in every type of habitat and are typically difficult to eradicate. Read more about invasive species around the globe and efforts to stop their spread.
The clock is ticking for the rats, possums and weasels that have invaded New Zealand over the past few hundred years. That's because the country plans to eradicate these invasive predators that threaten its native species by the year 2050.