Unless it's your pet mouse or rat in a cage (which may still cause some family members to jump on a chair if it gets loose), any wild rodent in your home is cause for concern. In addition to startling you with unexpected sightings, rodents such as mice and rats can contaminate food, chew up important papers, damage electrical wiring, and spread disease. In addition to fires caused by when the insulation on electrical wiring is chewed through, these rodents can carry diseases such as the hantavirus, which is transmitted through accidentally inhaling dust containing an infected rodent's dried urine.
It can be quite difficult to completely eradicate rats or mice that have infiltrated your home and established hidden nesting areas, so it's best to prevent infestations before they can happen. When you do find your home playing host to mice, rats, or other unwanted rodents, take whatever measures necessary to remove those pests and block their entry points into your home.
Signs of Rodent Presence
When a mouse or rat decides to visit, it often goes unseen—at least at the start. Usually, signs that rats or mice are present include small dark droppings (feces) found along walls or in places where food materials are present. You may notice chewed holes in boxes and bags of dry goods in a pantry, in pet food bags, or in bags of grass seed in the garage.
Close inspection along baseboards or near any holes in the floors, such as where radiator pipes come through, may show rub marks or gnawed areas where the rodents have chewed to gain free access. In hidden areas beneath cabinets, you may find small nest areas filled with shredded paper or wood shavings.
If you have pets, your dog or cat may exhibit alert behavior, sensing the presence of a rodent. And you may even hear sounds of scurrying or scratching in the walls or floors, especially at night when the house is silent and dark.
10 Tips for Keeping Rats and Mice Out of Your Home
The most effective way to control a rodent population in your home is prevention. With a little bit of garage cleaning, yard work, and caulking, you can avoid the major hassle of extensive cleanup that is necessary if even just a mouse or two gets into your house. Here are 10 suggestions on how to keep mice, rats, and other rodents out of your house.
- Block all entry points. The single most important preventive measure you can take is to inspect the foundation and walls of your house and make sure any potential entry points are blocked. The fall season, when rodents are seeking to get in from the cold, is an especially good time to run your inspection tour. Mice can enter through the smallest cracks, so block foundation cracks with a masonry repair material, and inspect joints around windows and doorsills for cracks that might allow rodents to enter. Make sure weather seals along the bottom edges of garage doors are in good shape.
- Don't feed the birds. The seeds and ground grains that go into most bird-food mixtures are a delightful treat for rodents, as evidenced by the presence of squirrels (larger cousins to rats) that frolic around any bird feeder. Feeding the birds is an admirable hobby, but you shouldn't be surprised when mice and rats are drawn to the ground around your feeders. If you must feed birds, keep your feeders as far from the house as possible.
- Don't store pet food in bags or cartons. Transfer dog and cat foods to sealed, airtight storage containers immediately after buying them. More than one homeowner pouring a bowl of dog food has dumped out a squeaking mouse at the same time. Dry pet foods are mana from heaven for rodents, so make sure to store them in tightly sealed containers well above the floor.
- Keep garbage bins sealed. Garbage bins kept alongside the house or garage will be a siren call to rats and mice (and maybe bigger pests, such as raccoons or stray dogs and cats) unless they are kept tightly sealed with airproof lids. If possible, keep these utility containers as far from your house as you can.
- Keep foundation plantings in control. Dense shrubs and garden planting that butt up close to the house provide hiding spots for mice and rats as they seek entry holes through foundations or walls. Shrubs along foundations should be planted a few feet away from the foundation, and make sure keep the soil level low enough that mice cannot squeeze their way up behind the siding.
- Keep dry food goods in sealed containers. Flour, sugar, and other food kept in bags or paper cartons are easily broached by rodents. Instead, keep these foods in tightly sealed plastic or metal containers on high shelves or in the refrigerator. Rodents will have no incentive to take up residence in your house if they don't smell any source of food.
- Keep floors and countertops clean. Casual housekeeping that fails to promptly sweep up spilled crumbs or food scraps from floors or countertops is an invitation for mice and rats. Never leave uneaten bowls of pet food in dishes on the floor, since pet foods might as well also have the label "mouse food" printed on the bags. Homes with pet birds can be especially susceptible to harboring mice that love to eat seeds scattered on the floors beneath bird cages.
- Keep doors closed. Garage doors left wide open can be an invitation to rats and mice, especially in the fall when these rodents are seeking to find a warm place as winter approaches. Get into the habit of closing your garage door immediately after entering or exiting with your car, and also keep side entry doors to the garage closed. Keep sliding patio doors and basement windows closed, or at least protected with screens, to prevent rodents from entering. Never leave a garage door, or other entries open overnight, as the dark hours are when rodents are especially active.
- Get an aggressive cat or dog. There is some debate about this since some people argue that the presence of pets actually increases the likelihood that you will have mice or rats in the house. Because pet food is always present in a house with pets, rodents may find your home to be a good source of food. But a truly aggressive cat with claws intact or a dog species such as a terrier with a reputation for hunting small animals often catches rodents before they can take up housekeeping and form nests and reproduce.
- Keep a few rodent traps set. Mostly as a diagnostic measure, keep a few rat or mouse traps set around the house where you can see them. This can help alert you if rodents are finding entry into your home. It is much easier to catch one or two mice or rats at the start of an infestation than to deal with it after a whole colony has set up a home in your walls. If the idea of killing mice bothers you, there are live traps you can use—although turning live mice free to roam outdoors may not make you popular with your neighbors. Some people routinely keep rodent poison baits set around the house, but this probably isn't the best idea, since these toxic baits can be found and consumed by pets. Never set poison baits outdoors, since squirrels and pets will find and eat them. Rodent poisons are a major cause of pet poisoning in the United States, and indoor mice that are killed by poisons may die in the walls, leaving you with the issue of their decaying remains.