Why the invasive rodent species nutria are such a problematic pest

Q. What are nutria, and why are they now considered a pest?
Nutria (or coypu) are like gophers on steroids.
Since they live near water, they are often mistaken for beavers or muskrats. There are some very big differences, both in appearance and behavior. Adult nutria are about two feet long and have a long, rat-like tail that can reach up to 18 inches long. They have long white whiskers, white muzzles, and dark yellow Austin Powers-like teeth. They dig and destroy flood control levees and they e