<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/nutria_0.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/nutria_0.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/nutria_0.jpg?v=ap&w=980&h=551 800w" > Nutria are an invasive species that destroys wetlands. (U.S. Department of Agriculture National Invasive Species Information Center)

At a Glance The giant rodents dig under levees and other infrastructure and chow down on vegetation crucial to native habitats.

They reappeared in California in the 1970s.

As of March, the state had killed more than 400 nutria. California's Central Valley is battling an invasion of destructive, burrowing nutria that threaten the region's waterways and wetlands.

A giant rodent with an oversized head, humped back and protruding bright orange front teeth, nutria are among nature's most cringe-inducing creatures. They're also one of the most damaging to aquatic habitats, digging under levees and other infrastructure and chowing down on vegetation crucial to native habitats, according to a U.S. Department of Agriculture.

Sometimes called a swamp rat or swamp beaver, nutria are native to South America but were brought to the U.S. in 1889 for their fur. When that market collapsed in the 1940s, thousands of nutria were released into the wild. Since then, they've been found in 22 states and are considered established in 16.

They've devastated wetlands in Maryland along the Chesapeake Bay and in other areas, but they are probably most well-known in Louisiana, where the state pays $6 for every nutria caught by hunters.

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Nutria destroy the banks of ditches, lakes, and other bodies of water as well as damage crops. But, the USDA says, their most notable impact is the permanent damage they cause to marshes and other wetlands, where the problem is exacerbated by climate change.

In these areas, nutria feed on native plants that hold wetland soil together," the USDA says . "The destruction of this vegetation intensifies the loss of coastal marshes that has been stimulated by rising sea levels."

Nutria were believed to have been eradicated from California in the 1970s. But two years ago, one showed up in a beaver trap in Merced County, according to an article earlier this year in the Los Angeles Times. The state launched an eradication program in 2018 and as of March 410 nutria had been killed , the San Francisco Chronicle reported.

Most recently, California Congressman Josh Harder introduced legislation that would provide $7 million to help eradicate nutria from his state.

Valerie Cook, a manager of California's eradication program, said nutria can devastate wetlands which in turn can interrupt flight paths for migratory birds, and weaken infrastructure crucial to agriculture and flood control.

“This is really like the trifecta of damage even far beyond what’s felt within the other states,” Cook said.