What harm can rats and mice cause?

Rats and mice can pose a threat to health and property. They cause damage to buildings by chewing on insulation, sidings, and wallboard. They also eat a variety of stored food. These rodents often contaminate food that they do not eat, which can lead to food poisoning.

All 3 types of rodents can also spread diseases, which are carried on their feet. Diseases can be spread by their bite, urine, or droppings. The ticks and fleas carried by rodents can also spread diseases.

Rats and mice have babies often, so it is important to find and get rid of them. Even if you do not see an actual rodent, the size of the droppings can tell you if there is a mouse or rat. Mouse droppings are approximately 6.35 mm (1/4 inch) long, and rat droppings measure up to 19.05 mm (3/4 inch) long.

How can I prevent rodents from living on my property?

There are steps you can take to prevent rodents on your property.

Eliminate food and water sources:
  1. Keep all garbage in metal containers with tight fitting lids.
  2. Compost kitchen waste in rodent-resistant containers. Do not throw meat, bones, grease, fish or other food scraps into the compost.
  3. Ensure the compost is away from the house. Properly maintain the compost by stirring and adding lime every few months.
  4. Remove fallen fruit and nuts from your yard.
  5. Remove pet food right after feeding and do not leave it outside overnight. Clean out waste and food from pet pens and enclosures.
  6. Equip bird feeders with trays and clean spilled seeds often.
  7. Repair any plumbing leaks to remove collected water. Cover pools and whirlpools when not in use.
Eliminate hiding and living places:
  1. Do not plant shrubs or flowers close to buildings. Keep a space clear between buildings and plants and allow 15 cm to 20 cm (6 to 8 inches) under plants. Trim grass and ditch areas.
  2. Remove unused piles of lumber, old sheds, or buildings.
  3. Do not store old cars or furniture outside.
  4. Store lumber and firewood on stands 30 cm to 45 cm (12 to 18 inches) off the ground.
Protect buildings:

House mice frequently find their way into homes in the fall of the year, when outdoor temperatures at night become colder.
  1. Eliminate all openings through which they can enter a structure.
  2. Seal cracks and openings in building foundations and openings for water pipes, vents and utilities.
  3. In order for the mouse not to chew or pull out patching compounds, the patching materials need to be smooth on the surface.
  4. Doors, windows and screens should fit tightly.
  5. All food that is stored, processed or used should be made mouse-proof. Dried grain and meat products should be stored in glass jars, metal canisters or other reseals able airtight containers.
  6. Cover crawl spaces, fresh air and attic vents with 6.35 mm (1/4 inch) metal screening or steel mesh.
  7. Repair cracks in cement footings and foundations.
  8. Build sheds on concrete slabs.
  9. Install 6.35 mm (1/4 inch) hardware cloth inside your compost.
Feeding Habits:

Mice normally feed 15 to 20 times per day and will eat pretty much anything a human will eat. Food preference is cereal or seed, but also gnaws through insulation or wires, sheet rock, storage boxes, etc. Mice are nibblers. They do small amounts of damage to many food items in "home range", rather than doing extensive damage to any one item.

While mice are nibblers and feed many times in many places, they have two main feeding periods, at dusk and just before dawn. They have to consume about 10% to 15% of their body weight every 24 hours and require extremely small amounts of water.

Food Contamination and other Damages:

A mouse may contaminate your food supply with its feces and urine. House mice gnaw through electrical wiring, causing fires and failure of freezers, clothes dryers and other appliances. A mouse's tooth mark is about 1/8 inch wide.

Disease & Sanitation Factors:
  1. Mice droppings sometimes are confused with droppings from the larger species of roaches, such as the American roach.
  2. Mice droppings are smooth with pointed ends, and are 1/8th to 1/4 inch long.
  3. In six months, one pair of mice can eat about 4 pounds of food and during that period produce some 18,000 fecal droppings.
  4. Deer mice are a primary vector of Hantavirus infections which cause hemorrhagic fevers.
  5. Mice may infect food with their droppings transmitting such organisms as salmonella and the microscopic eggs of tapeworms.
  6. Mice transmit disease in a number of ways including biting, infecting human food with their droppings or urine, indirectly via the dog or cat and bloodsucking insects.

As with the House Mouse, control can be accomplished by snap traps, glue boards or multiple mouse traps. They have a tendency to store food. If using a baiting program it is best to use a bait blox . Baits should be placed in the same way as for the House Mouse, close to the suspected activity.