Not every mouse carries disease, but it is impossible to know whether a rodent is infected by appearance alone. Therefore, all rodent exposure should be treated as a potential risk. Mice may play a role in the spread of hantavirus, leptospirosis, salmonella, and certain parasites. The risk increases especially in areas contaminated with rodent feces, urine, or saliva. If signs of rodents are seen in homes, warehouses, basements, barns, or garages, food sources should be sealed, entry holes should be blocked, and cleaning should be done safely. The key prevention strategy is minimizing direct and indirect contact with rodents.