While we prep for cold weather, animals do, too. Fall is prime time for an increase in rodent activity in your home. While small, mice and rats can cause big problems. They chew on everything, causing property damage and potential fire risks when they gnaw on electrical wiring and build tinder dry nests in dark corners. They can spread disease, on their own, through the parasites they carry (their fleas carried the Black Plague) or through their droppings (such as hantavirus).
How to Tell if You Have Mice in Your Home
It’s probably more common to see mouse droppings or mouse damage before you see the mice themselves, as they are nocturnal. When I was a kid, the little buggers would dry me crazy at night running around up in the attic. Thankfully we didn’t get rats in the house, but they would sometimes show up in the outbuildings around the farm.
Identifying Droppings and Urine
Killum Pest Control offers an excellent online guide to interpreting rodent signs. Please visit their site for more information, but I’ll just share briefly their comments on dropping and urine identification.
Droppings. Fresh droppings of feces usually are moist, soft, shiny and dark, but in a few days they become dry and hard. Old droppings are dull and grayish and crumble when pressed with a stick. The roof rat’s droppings are up to 1/2 inch long, spindle shaped and curved in contrast to Norway rat droppings which are about the same length but comparatively blunt. Mouse feces are small, averaging about 1/8 inch long, and are pointed on both ends.
Urine. Dried rodent urine will fluoresce bluish white to yellowish white. Commercial black lights often are used to detect rodent urine, however observing fluorescence is not a guarantee that rodent urine is present. Numerous items will fluoresce under a black light, including optical bleaches found in many detergents and lubricating oil. For positive identification use a Brom Thymol Blue Urease Test. Place the suspected material on Urease-Brom Thymol-Blue test paper. Moisten with water and cover with a glass. If a bluish spot appears after 3 to 5 minutes, it is rodent urine.
Mice commonly mark their trails with urine (yes, I know, you probably didn’t really want to know that…) so that other mice can follow their tracks to food sources. One source I read said that they produce 50-60 droppings per night – ewwww… Once you’ve found their way into your home, you need to block it, otherwise they be right back in via the pee track highway. They can climb, too – like mini rodent ninjas.
You may also find food stashes and nests in out of the way corners. I remember finding a mouse nest in the back of an old school desk in my room. Gnawing damage is another dead giveaway. My mom had a cardboard box of old cooking magazines inside a wooden cabinet, and the mini rodent ninjas still found their way in and chewed the edges of the magazines.
How to Keep Mice Out of Your Home
To keep these critters out and keep your family safe and your goods protected, follow these simple steps.
- Remove Food Sources
Bird food, pet food and other edible odds and ends (even cardboard) that tend to pile up in garages are like mouse nirvana. Crumbs under the couch are a gourmet treat, and a cookie lost by toddler is a mouse family buffet. Seal all food (for pets or humans) in solid containers, not just in bags. (Rats can and will chew through plastic bins, so be warned. You need to use metal containers to keep them out.) Plastic garbage cans or Rubbermaid tubs will generally keep mice out. Clean, clean, clean! Gaps between appliances like stoves or refrigerators and cabinets can collect crumbs where they are difficult for you to clean, but handy for mice to dine. Remember, if they can get their heads into a space, their bodies can get in, too.
- Seal Openings
This is the probably the toughest but most effective way to keep mice out – seal openings. As I mentioned above, if a mouse can get its head though, the body can go through as well. The little pests only need about a ¼ inch (0.6 cm) wide opening. They can jump – up to 18 inches (I told you – mini rodent ninjas), travel upside down (you bet), and crawl along an electrical wire (piece of cake). If you can stick a #2 pencil through a hole, a mouse can probably use it to get into your home.
When you find holes, you want to try and seal them as strongly as possible. The Internet Center for Wildlife Damage Management recommends:
Steel wool, copper gauze (Stuf-it® brand) or screen wire packed tightly into openings is a good temporary plug. For long-term or permanent repair, mix a quick-drying patching plaster or anchoring such as Fixall® into a wad of Stuf-it® before pushing the material into the hole, and smooth over the outside. If steel wool is used, rust stains are likely to result. Holes 3 inches (8 cm) or more in diameter should be covered or backed with 1/4-inch (0.6-cm) woven/welded hardware cloth prior to filling with a good patching compound. Another backing material available is Strong PatchTM (D. P. Wagner Mfg. Inc.), a 6 x 6-inch (15 x 15-cm) sheet metal patch to cover holes up to 5 x 5 inches (11 x 11 cm). It has a self-adhesive backing and a mesh on the surface for better adhesion of the patching compound or other texture.
Visit their site for diagrams and more extensive information on making outbuildings more rodent resistant.
- Reduce Outside Habitat
If possible, reduce the amount of mouse habitat outside your home to reduce the number of mice inside your home. Trim trees and shrubs away from the home. Clean up debris, brush piles, and other hiding spots where mice may take cover. Keep your compost bin(s) as tidy as possible (opossums and rats like to raid the compost, too). I saw one site recommend moving wood piles 100 feet from the house and raising them one foot off the ground. Obviously they don’t live in Wisconsin. The mice will have to stay in the wood pile – their nests make great tinder.
Best Ways to Remove Mice that Are Already in Your Home
Your three main options are cats, traps and poison. I’ve come to love my kitties, but it’s not practical for everyone to have a cat or cats in the house, and not all cats are good mousers. (I’ve had friends tell me about their cats who watch the mice run right past them.) Poisons do work, but not immediately. The mice will crawl off and die somewhere and potentially smell really nasty, plus who wants mummified mice sitting around their house? Poisons can also be a danger to children and pets. I remember when my eldest found some ant poison I had put in the back of the closet when he was a toddler. He was fine – Terro is not toxic in small amounts – but it gave me a good scare.
Your basic wooden trap is cheap and readily available, but can sometimes be hit or miss. A friend of mine was complaining recently that her mice kept stealing the bait but not getting caught in the trap. Two new trap types that look promising to me are Jawz Easy To Set Plastic Mouse Trap and Kness SNAP-E Mousetrap. I haven’t tried them yet, but the online reviews are very good. Humane traps are also available, but one site states that you need to take your mouse at least two miles away to make sure it will not return. I am not a mouse chauffeur, and I don’t think it’s right to share my mice with my neighbors.
My mom’s favorite bait was peanut butter, which they can’t grab and carry off. When you’re placing traps, try to put them along walls where you believe mice are moving. Block their path with a buffet of your choosing instead of letting them into your cupboards. Two traps side by side are better than one, as they will have a tougher time escaping both (remember – mini rodent ninjas). Set the traps perpendicular to the wall (see photo). Check traps daily, empty and reset as needed. Odor from one mouse may help attract the next mouse, but having a deceased mouse hanging around doesn’t do anyone any favors.
How to Safely Clean Up After Mice
Because of the risk of hantavirus and other illnesses, care should be taken when cleaning up mouse droppings/remains, especially in quantity and/or in enclosed areas. (Information adapted from Environment, Health and Safety Online.)
- Wear gloves, either rubber gloves or work gloves you can wash in hot water
- Spray the droppings first with 3% hydrogen peroxide, then with white vinegar. This will kill 99% of bacteria. A bleach water solution or disinfectant is also and option.
- Wipe up droppings with a paper towel, throw towel in garbage
- Clean area with disinfectant solution or hydrogen peroxide/vinegar combo
- Wash hands with soap and water before and after removing gloves
If dealing with large amounts of droppings, you may need professional help, or at the very least please wear a face mask. Please be careful! Your county extension office may be able to provide more information on any known rodent related disease outbreaks in your area.
Treat nesting materials and dead mice similarly. Always wash hands thoroughly after touching contaminated materials.
I hope you find this article useful. If so, please share it with your friends. Don’t forget to stop by and visit Common Sense Homesteading.
Laurie Neverman was raised on a Northwest Wisconsin dairy farm where frugality and providing food for the family were a way a life. Now she lives with her family in Kewaunee County in a green home they designed and built. On 35 acres, the family tends to large organic gardens containing over 100 varieties of fruits and vegetables, most of which are heirlooms. They freeze, water bath can, pressure can, dry, and ferment to preserve food, and use the root cellar, cool storage, cold frames, and green house to extend the harvest without additional energy inputs.
Laurie has written for a number of local and national publications including Taste of Home and Countryside magazines, The Healthy Independent and Healthy Thoughts.