Of Mice, Men, and Their Cars

Published in Old Cars Weekly magazine in 1998

Every spring we learn of mouse damage to cars, especially those not stored in carbags. They create havoc from yucky odors, much frustration and hundreds of dollars of expense from damaged interiors, wiring and more. Using a carbag provides protection as close to 100% as anything else. However, the guarantee is not 100% as eliminating these furry creatures can be tricky.

We have information about controlling these critters from several reputable sources. They include professionals from local/county or state Public Health Department rodent control divisions, state university Cooperative Extension Services, United States Environmental Protection Agency (EPA), reference text books and Federal Trade Commission (FTC) reports. Here are some information which may be helpful if you have or have had mouse problems.

First, have a bit of respect for the task of controlling rodents. Since mice and rats are known to carry and transmit diseases, contaminate food (enough to feed 200 million people), and damage buildings from gnawing resulting in great economic loss, it makes sense to have good practices in place to prevent or eliminate them. In fact, more than 120 million dollars are spent every year on rodent control programs in the United States.

The house mouse is very adaptable to its surroundings. Cold weather brings them into buildings, cars, and houses through the smallest of openings, a 1/4 inch space is enough. They find shelter in out of the way places where nesting material and food is close by usually within 10-30 feet. Preferred nesting material like paper, insulation, and furniture stuffing may be used in traps as bait. Mice are food samplers, nibbling here and there needing only about one-tenth of an ounce a day. Food is often their source of water, not needing the liquid stuff to survive. They sexually mature in 6 to 10 weeks after birth and may have 5 to 10 litters a year of five to six young. With these habits and abilities, you can imagine having a healthy mouse population in a short time.

It seems that professionals all agree to a combined pest control approach for managing mice and other rodents. It is called ‘Integrated Pest Management in Rodent Control’ and follows four (4) important steps. They are:
1. Rodent Inspections
2. Sanitation
3. Rodent Proofing (exclusion)
4. Population Reduction (rodent killing)
a. Trapping Programs
b. Rodenticide (rodent poisons) Programs

Doing any one of these steps may help reduce the number of rodents present. You may want to try some yourself, or request help from a professional such as a recommended, and licensed pest control firm. However, the most effective and efficient long-term control will happen when all four steps are used.

Inspections
In some areas a phone call to professionals in Public Health Departments or Cooperative Extension Services may be able to do a site inspection and make recommendations for control. What they look for, which you too can do, is look, smell, or listen for rodent signs such as droppings, gnawing damage, rodent odors, and/or runways among other signs.

Sanitation
This step requires a “clean up your act” attitude. Get rid of food and shelter for mice. This will go a long way in reducing the number of rodents as they need both to survive. So good housekeeping practices are a must! Mice need very small amounts of food and no free water if their food source provides it. Cleaning up inside and outside of buildings can be a real chore. Some things to remember are: proper refuse management, storage practices, and feeding of pets and wildlife. Consider eliminating rubbish piles, improve on garbage handling (rodent-proof containers), removal of grass and weeds near buildings, piles of stuff like lumber should be stored at lease 18 inches off of ground. Eliminate or modify dark, out of the way areas like under, behind, and inside cabinets, corners and the like. One reason mice like to get into cars stored without a carbag is the availability of many nooks and crannies. Headliners provide stuff for nesting, fabric seats with food crumbs for eating and nesting, and electrical wires that look like grass stems to be “chewed down” for the expected seed. All these are fair game for these adaptable invaders.

Exclusion
This means keeping rodents out of a building where your car is stored. So you need to rodent-proof as much as possible. This chore is difficult at best as mice can enter such small openings. Places where pipes and utility lines enter a building as well as vents and warped doors are excellent places for them to enter. Use heavy sealing materials that resist rodent gnawing like coarse steel wool, concrete mortar, hardware cloth, and sheet metal to close these areas to help keep mice out.

Population control: trapping
Refer to the professionals in your area for determining which of the several types of traps and baits are best for your situation. Use plenty of traps (six or more in a kitchen for a few mice), placed in active areas (remember mice travel only short distances for food and water), and use baits like bacon, nuts, peanut butter or hot dog pieces that are “sniffable.” They have excellent senses for smell, taste, and touch. Using bits of nesting material like cotton balls are also recommended for bait.

Population control: chemical
Safety in handling and using chemicals for rodent control must be the first consideration! You ought to consult with professionals when using chemicals. Some chemicals used for mouse/rat control are highly toxic and can be fatal to humans, pets, or livestock if eaten in only vary small amounts. These chemicals usually cause death after several or only one feeding depending upon the type. This is true for chemicals which clot blood, act on the nervous system or have different ways in which death occurs. However, there are several different doses needed and different types of materials available. Keep in mind that you need to know the product you are working with and use good safety practices such as keep products from children, pets, and live stock, to prevent contamination of food stuffs and clothing. Also, be sure to use warning labels, follow instruction, and wash hands well after handling thesse chemicals, among many other considerations.

Periodically new devices and gadgets make it to the market place for rodent control. Check with your local professionals before purchase to determine if they work. One group of devices we feel necessary to comment on are ultrasonic devices. We found convincing information about why not to use these ultrasonic devices for pest control in several places. Statements from two of them sum it up:

1) A report about a FTC action that recently shut down production for two of these devices. The article was entitled, Sonics Sunk Again” “Another ultrasonic device bites the dust…an FTC action similar to actions taken against other ultrasonic devices. In all probability, someone else will develop a ‘better’ device and will make claims that are too good to be true. Save your money because if the claims seem too good to be true, they probable are.” and

2) A chapter from “Prevention and Control of Wildlife Damage,” a publication from Purdue University states that “The advertising claims for many commercial devices are completely unsubstantiated by scientific research. Since commercial ultrasonic devices are very expensive and of questionable effectiveness, they cannot be recommended at this time as a solution to rodent problems.”

We believe what these reputable sources tell us. What do you think?

Effective odor control:
So your car smells like mouse urine…or other odors. Over heard one year at the Meadow Brook Concours de Elegance in Rochester, Michigan: two collectors were discussing effective ways to get rid of mouse and mouldy odors in antique, stored cars. One gentleman said he had great results from sprinkling a pound of fresh coffee grounds inside the car. After standing over night with doors and windows closed, he vacuumed the coffee grounds off the floor mats. Voila! No more mouse odor.
We have tried this approach with great success. The process is short, inexpensive, and coffee odor is more satisfying than one a mouse leaves behind.

Pest Control & Sanitation Newsletter. Copesan Services, Inc. Nationwide Pest Management. Sonics Sunk Again. 1st Quarter, 1995.
House Mouse by Robert M. Timm, 1983. Pages B/27-B/42 in Prevention and Control of Wildlife Damage. Cooperative Extension Service, Institute of Agriculture and Natural Resources, Univ. of Nebraska
Rats and Mice. 1988. Pages 307-331 in Truman’s Scientific Guide to Pest Control Operations, 4th Edition, Purdue University. Edgell Com. Project