Aquatic Plants
Nutrias eat various aquatic plants including water celery and watercress. They also eat plant roots. Humans have used nutrias in Texas and some other areas of the U.S. to cut down on the overgrowth of vegetation in ponds and lakes. These South American semiaquatic rodents frequently consume so much food that they cut down on the natural food sources of ducks and other aquatic animals.
Insects
Nutrias are opportunistic scavengers that will eat most food items they encounter. Some nutrias eat small aquatic insects, including water skates. They may also eat insects flying near water such as flies and ants.
Human Scraps
Nutrias residing in heavily people populated areas have grown accustomed to eating scraps that restaurants throw away. Though they prefer vegetable matter, they also eat small pieces of meat, sweets and bread. This often leads to infestations of the rodents in commercial districts.
Food Overconsumption
Nutrias are prolific breeders. ScienceDaily reports that, on average, a nutria will give birth to five litters a year, and these litters can contain more than a dozen offspring. This in conjunction with their varied diet has led to massive overconsumption of plant and vegetable matter in marshes and ponds. Especially in areas where nutrias are an introduced species, they pose a danger to the ecological balance of wetlands.