The coypu, a semi-aquatic rodent native to South America, was introduced to France in the 19th century for its valuable fur. Initially, the animal was raised in enclosures to supply a market that sought to mimic the appearance of more expensive furs, such as those of otters or beavers. The coypu was also used in the production of felt for hats. However, as the fur industry declined in the 1930s, poorly secured enclosures and deliberate releases by financially struggling breeders allowed the species to escape into the wild. With no natural predators in France, the coypu population grew rapidly, with each pair producing up to 90 offspring in just two years. The French government had supported the coypu breeding industry in the 1930s, but as the demand for coypu fur waned, the industry became unprofitable. This led to the release of many animals into the environment, where they quickly spread across the country. The coypu thrives in France's wetlands and waterways, following the hydrographic network. Its population saw a dramatic increase in the 1970s, leading to significant environmental and agricultural challenges. Polleniz, an organization that coordinates efforts to control invasive species like the coypu and the muskrat, reports that more than 300,000 of these animals are captured annually in the Pays de la Loire region. However, this figure is not a national statistic and includes both coypus and muskrats, which make up the population. The muskrat accounts for less than 20 percent of the total. Between 2005 and 2016, the number of captures has steadily increased. French law allows trappers to control these species year-round, and a 2016 decree published on Légifrance authorizes the trapping and destruction of coypus and muskrats across the country. In a recent intensive operation in Loire-Atlantique, 36 volunteers removed 986 coypus and muskrats in three weeks using about 250 cage traps baited with carrots. Volunteers were paid 3 euros per captured animal. The damage caused by coypus is primarily mechanical, as they dig burrows in riverbanks, weakening them and posing risks to dikes. The soil they displace into waterways accelerates the filling of ditches and canals. Health risks are also a concern, as the coypu can carry leptospirosis and the liver fluke, a parasite that mainly affects sheep. A 2001 study published in the journal Veterinary Research found that 8 to 40 percent of coypus may be carriers of the liver fluke. In the 1980s, the coypu invaded the Poitou Marsh, prompting mandatory efforts to control its spread. Despite these efforts, the coypu population remains difficult to quantify due to its widespread and elusive nature. The Coordination Rurale, an agricultural advocacy group, suggests that eradication is unlikely. Instead, they are exploring new methods such as connected traps and a contraceptive vaccine to manage the population more effectively.