The giant rodents called nutria are an invasive species of rodent that can grow to three feet from their nose to the tip of their tail.
They are a threat to agriculture because they can wipe out wetlands, disrupting water delivery and flood control systems.
The U.S. Fish and Wildlife Service says it has captured more than 400 of the animals across the San Joaquin Valley.
The nutria have a weakness for sweet potatoes, so valley farmers have donated five tons worth to help lure the rodents into traps.