William Shakespeare is to blame for one of the most highly-invasive species living in the United States.
Back in late 19th century, a Bronx-based drug manufacturer Eugene Schieffelin decided he wanted to introduce every avian species in the Bard's literature to the United States. To star, he released 60 European starlings, which were imported from England, into New York City's Central Park in 1890. The following year, he added another 40 to the wild.
More than a century later, there are starlings living in all 50 states, flying in flocks of up to 1 million.
The species easily acclimated to cities and natural habitats, such as grasslands, but this does not mean it simply assimilated into the U.S. ecosystem.
Not only do European starlings damage agricultural crops, carry diseases like salmonella and compete with native species for territory and food, but their tendency to fly in massive flocks has actually resulted in a loss of human life.
In 1960, a plane taking off from Boston's Logan Airport flew into a cloud of 10,000 starlings. The destroyed engines sent the plane plummeting to the ground, killing 62 humans aboard.
These birds are not the only common creatures that simply don't belong in the United States. There are dozens of plants and animals brought to North America by human error that are now disrupting the ecosystem.
Check out the gallery below for other invasive species out of place in the United States:
Invasive species in the United States
13 invasive species wreaking havoc in the United States