Commensal rodents consist of the Norway Rat, the Roof Rat, and the notorious House Mouse. The only possible category where they could be considered beneficial would be as garbage removal, and that is stretching it even for devoted animal activists. These rodents are not native to the United States, they came from Europe with early explorers and settlers. They include salmonellosis, plague, leptospirosis, hantaviriruses, and rickettsial pox. Rodents are often infested with fleas which they often share with those with whom they live.
Rodents consume and contaminate significant numbers of the worlds food supply every year.
Rodents cause extensive damage to properties by gnawing on wood and wiring, often causing fires. Rodents cause some people to jump on chairs and scream, often falling and braking bones. The House Mouse is found throughout the United States. They are omnivores, feeding on cereal grains, seeds, fruits, vegetables, and meats. Seed is the preferred food.