How to keep mice out of your house

It started as an annoyance and quickly grew into a serious problem. A chewed up roll of shop towels, tattered rags, rice-sized feces scattered on the counters — the signs were clear. A family of mice moved into our garage.

It didn’t take long for them to overstay their welcome. When I discovered nearly a full bag of bird seed had been eaten, I knew they had to go.

The mice inhabiting our detached garage have become a problem, and it seems to be a growing problem. After finding a pile of sunflower seed shells behind the radio, I cleaned the garage thoroughly and removed any other sources of food. However, I didn’t consider the shop towels or microfiber rags we leave out there. And so, they were left with a perfect source of warm winter bedding.

We started setting traps when we realized removing their food source didn’t deter them from our garage. We stashed the rags and shop towels in sealed plastic containers, cleaned up their poop and left behind snap traps baited with peanut butter. To our surprise, we had early success. Of the first four traps we set, two killed mice.

Too much success

The peanut butter worked so well and the results came so effortlessly we decided to put out more traps the second time. Six traps primed with peanut butter, adorned the wooden baseboard that runs along the walls in our garage. It must be to-die-for because this time we went 5-of-6.

Killing seven mice in such a short span of time can make you feel one of two ways. Either you feel great that your success rate is 70 percent or you’re a bit concerned you’re so successful because you’ve got a big problem and you’re only scratching the surface. I relate more to the latter set of emotions, which has inspired me to take precautions and make sure I’m taking the necessary steps to get my garage back and keep it mouse-free.

Related:

• How to keep rodents from overwintering in your house, outbuilding or barn

Ohio mice

There are six different types of Ohio mice. Some are more likely to inhabit your home than others. It’s important to identify which type is in your house to understand its reproduction cycle, food and shelter preferences and basic habits.

Eastern harvest mouse. The Eastern harvest mouse is brown with a lighter colored belly. Its preferred habitats include old fields, marshes and wet meadows. It likes to eat seeds and grains but has also been known to feed on grasshoppers and crickets. Its breeding period stretches from May to November. Females will have litters of two to five young after a gestation period of 21 days.

House mouse. The house mouse is a small grey-brown mouse with a grey or buff belly and scaley tail. These mice most commonly live near humans, usually living in buildings and occasionally fields. They eat plant matter, insects and meat. The house mouse reproduces often, having litters of three to 11 young after a gestation period of 18 to 21 days.

Meadow jumping mouse. The meadow jumping mouse is easily distinguished by its olive-yellow fur, long tail and large hind feet. It prefers to live in low, moist grasslands, avoiding wooded areas. The meadow jumping mouse will breed after hibernation in April or May. Females have two to three litters of four to five young a year after 18 to 21 days of gestation.

North American deer mouse. The deer mouse is small like the house mouse, but its color ranges from pale gray to deep reddish brown. Its tail is bicolored with white below and dark above. The deer mouse is very adaptable, inhabiting forests, grasslands, brushlands, agricultural fields and deserts. They eat a wide variety of plant and animal matter including seeds, fruits, flowers and insects.

White-footed deermouse. The white-footed deermouse can range in color from a pale to rich reddish brown with a white belly and feet. It is also characterized by a tail that is shorter than the length of its body. The deermouse can live in a variety of habitats, but prefers woody or brushy areas. It is the most abundant rodent in mixed forests and agricultural fields in the United States, according to the Ohio Department of Natural Resources. The deermouse’s diet consists of seeds, nuts, fungi and insects. It produces two to four litters per year from March to June, having two to six young in a litter after a gestation period of 22 to 28 days.

Woodland jumping mouse. The woodland jumping mouse can be easily identified by its yellow sides, brown back, white belly, large hind feet and long white-tipped tail. These mice prefer bushy areas near water and wet bogs or stream borders. They feed mostly on seeds, fruits, fungi and insects. Woodland mice reproduce from June to September after emerging from hibernation. They produce only one or two litters of three to five young per year, after a gestation period of 29 days.

Mouse Control

Once you’ve identified which type of mouse has moved into your home, it will be easier to get rid of it. And the sooner the better. As you discovered in the above section, mice reproduce quickly and your problem can escalate rapidly over the course of months.

There are many reasons to want to get rid of mice. Some people are creeped out by them. Some don’t like the mess they make. Some don’t want them damaging their home and the items inside. All are valid reasons, but it’s also important to note that they can be very dangerous to human health. Their urine can cause allergies in children, they can transmit human diseases and they can bring fleas, mites, ticks and lice into your home.

So how do you get them out of your house and keep them out?

It’s simple. You eliminate easy access to your home, make it harder for them to find food and reduce the amount of shelter materials laying around. This is a three-step process — sealing off entrances, sanitation and population reduction.

Sealing off entrances

The most permanent form of mouse control is eliminating all openings that they can enter through. You’ll need to seal any opening larger than 1/4 inch to exclude mice. Use rodent-proof materials such as copper mesh, hardware cloth and silicone sealant to seal any potential entrance. Make sure to tightly seal all cracks and openings in building foundations and openings for water pipes, vents and utilities with metal or concrete. You can eliminate gaps around pipes with steel wool and caulk or mortar. You can seal larger openings by using aluminum flashing or 1/4-inch wire mesh. Check to see that doors, windows and screens fit tightly, and consider installing door sweeps under doors.

Sanitation

Mice can survive on limited amounts of food and shelter, so it’s almost impossible to eliminate entire populations. However, limiting the availability of food, water and shelter can prevent an infestation. You can start by keeping your living areas uncluttered inside and out.

• Inside your home, you want to clean up crumbs and spills quickly and store food and pet food up off the floor in sealed containers with fitted lids.
• Reduce clutter, including piles of old newspapers, mail, boxes or any other sort of nesting material.
• Make sure you fix any leaky faucets and pipes inside or outside your home.
• Keep your yard maintained and free of debris piles.
• Dispose of trash regularly.
• Store firewood away from your home.

Although sanitation probably won’t eliminate mice, a lack of it will attract them and allow them to thrive. Try to eliminate places where mice can find food and shelter. They can’t survive in large numbers if they have few places to rest, hide or build nests and rear young with easy access to a food source.

Population reduction

Inside your home, snap traps are the best option because they don’t contain pesticides that can be harmful to your children or pets and they give you an opportunity to remove the body immediately. However, you will have to be mindful of where you put them, keeping them out of the reach of pets and children. The best places are places the mouse has been — places where you’ve found a nest, evidence of chewing, crumbs or feces. Usually, these places are hidden in dark corners, against walls where the mouse can move about undetected.

I like to use peanut butter for bait, but you can also try caramel or nesting materials of cotton balls or cloth. To avoid trap shyness, you can try baiting the trap and leaving it out unset until the bait has been taken at least once. Then bait and set the trap to get rid of the mouse for good the second time.

The best time to set traps is at night because mice are most active during that time. This can also be beneficial for you, allowing you to remove the trap during the day when children and pets are active.

Rodenticides

Poisonous mouse baits can be purchased in pellet form to eliminate pests. However, it’s not recommended that you use them in your home as they can accidentally poison a curious child or pet. You also run the risk of a mouse dying inside a wall. It will not only smell bad, but it could also attract insects.

Not recommended

Glue traps. Although they are non-toxic, it’s not a good idea to use them. When disposing of them, you’ll have to deal with the live mouse, risking getting bitten. And because they don’t kill the mouse right away, it could suffer a cruel, drawn-out death.

Box traps. Traps that capture the animal alive to be released elsewhere generally aren’t a good idea because relocating a mouse is very stressful for the mouse and survival isn’t likely anyway.

Noise machines. Mice get used to repeated noises, so these devices aren’t effective.

Related Content

• How to keep rodents from overwintering in your house, outbuilding or barn

Resources

• Penn State Extension
• University of Illionois Extension
• University of Missouri Extension
• Ohio Department of Natural Resources