Nutria — furry, swamp-dwelling rodents that look like 10-pound rats with webbed feet — are largely regarded as a nuisance in Louisiana's Cajun country. But they are wanted creatures nonetheless. Starting Wednesday, the state of Louisiana will pay a $4-a-tail bounty — officials prefer the term "incentive" — in hopes of wiping out 400,000 nutria this winter. The payment is part of an effort to save Louisiana's coast, which is disappearing at a rate of 35 square miles a year. Nutria, a non-native species that has overrun Gulf of Mexico wetlands since the value of their fur plummeted in the...