Perhaps the greatest disaster to ever hit American wetlands.

In terms of ecological impact, the only land creature that can compare to this large aquatic rodent is the sheep. Like sheep, Nutria will eat not only the tops of grasses, but will dig up the roots and eat those, too. They also chase native muskrat away.

This was dramatically demonstrated by an experiment at Maryland's Blackwater National Wildlife Refuge. Scientists erected fences that could only keep out Nutria. After a few weeks, the marsh on the nutria-free side of the fence sustained no damage, while the marsh on the nutria side of the fence was devastated.

Nutria will devastate a marsh so quickly that most environmental groups support nutria eradication efforts, including the use of old-fashioned traps to catch them.

Someone please supersede me.