Rodents   Damage: Rodents consume and contaminate food. They also gnaw on electrical wires, wooden structures, and tear insulation in walls and ceilings for nesting. Rodents can also transmit disease to humans, pets, and livestock. They have been found to transmit typhus, leptospirosis, trichinosis, and salmonellosis.  Detection and Treatment: The presence of mice and rats is usually detected by the damage they cause to food and structures, by their droppings, and by their nests. Treatment involves eliminating all entry points and population reduction by the application of rodenticides and traps. Learn more.