Kudzu was originally imported from the Orient as an ornamental plant and was widley used for erosion control. It took several decades before the U.S. government officially declared kudzu to be a weed.

The Gypsy moth was imported in the late 1860's from France by E. Leopold Trouvelot in an ill-fated attempt for silk production in Massachusetts. The moths escaped from the cages he had in his backyard. He understood the potential problems that could result from their escape and notified local entomologists, but no follow-up action was taken. Now they are a major threat to U.S. forests.

Coyotes, native to the western part of U.S., have increased in number over the last several decades and have spread across Mississippi all the way to New England. Since coyotes are known to prey upon livestock, thousands of coyotes are killed by man every year in the U.S. This is an example of a species being invasive over a great distance due to its own mobility.

Another type of invasive species is the Colorado potato beetle. It is native to the western U.S. and fed on native plants. When the potato crops were planted in that region, the Colorado potato beetle started eating potato plants. It now has become an invasive species, not only in the U.S. but also on other continents.