Each is a serious pest. Norway rats and roof rats came from Europe with the first explorers and quickly invaded the continent. After rats, the common house mouse is the second most destructive vertebrate in the world. Rodents spread a wide variety of serious diseases, including salmonellosis, plague, leptospirosis, hantaviruses and rickettsial pox. Rodents consume and contaminate significant percentages of the world's food supply every year.
Rodents carry fleas and other parasites into buildings.
Rodents cause a great deal of anxiety for occupants of infested buildings. Rodents cause extensive economic damage by gnawing on structures and wiring, causing fires. Look for these common signs. They may indicate an infestation of rodents. Droppings and urine are left wherever rodents travel or rest, especially in corners.