The Ultimate Guide to Rodent Control

It's every homeowner’s nightmare: you spot a tiny, furry creature sprinting across your floor, disappearing into a crack in the wall. Over the following weeks, you realize that these small, seemingly insignificant animals can do thousands of dollars worth of damage. From damaging your house and property, to threatening the health of your and your family, rodents are nasty, destructive little creatures. And what’s more, once they’re inside your house, it’s incredibly difficult to get them out—for each one you trap, three more emerge from the depths of your house, making it a tiring, seemingly never-ending task.

If you, like countless others across the country, have had to deal with rodents skittering around your house, chewing at the electrical wiring and leaving droppings everywhere, don’t worry—there are several simple ways to control a rodent infestation. Mice and rats are unpleasant creatures that invade your home, contaminate your food, and facilitate the spread of diseases. Dealing with a rodent problem can seem like an expensive, disheartening task, but in this article, we’ll go over some easy steps you can take to ensure that you and your family are the only ones living in your house.

What are the signs of a rodent infestation?

Luckily, rodents may be small, but they are far from subtle. The chances of you actually seeing a mouse or rat are rare, as they tend to be more active during the nighttime, but they leave behind plenty of telltale signs of their presence. If you believe that your house is overrun with furry intruders, there are numerous signs that can confirm your rodent infestation. The first, and usually most common, sign is the presence of rodent droppings. Rodent droppings can usually be found in food storage areas, such as kitchen cupboards and drawers, and in dark, enclosed spaces such as closet corners and behind appliances. The most number of droppings tend to be found near areas where the rodents are nesting or feeding—if you regularly find droppings in a certain area of the house, check the surrounding areas to try and find the source of the infestation. Surprisingly, inspecting these droppings can provide valuable information such as the type of rodent, the approximate number and age of the rodents, and the area of the infestation. Mouse droppings tend to be much smaller than rat droppings, at about ¼ inch, and are pointed on both ends. Rat droppings are approximately ½ inch, and can be either blunt or pointed at the ends, depending on the type of rat. If you find a variety of sizes, it’s likely that there are both babies and adults present. You can also get a good idea of how long the rodents have been in your home by examining the texture of the droppings—newer droppings are dark and moist, while older droppings tend to dry out and turn gray. Make sure to always wear gloves and a mask if you are handling rodent feces.

Another common sign of rodents is their signature unpleasant smell. Mice urinate often, and they are not picky about where they do it. If you frequently smell a musty, ammonia-like odor around your house, there’s a good chance that you have a rodent problem. However, rodent urine generally will not be extremely noticeable unless you have a larger infestation. If you have a pet, pay attention to their behavior—animals have a much better sense of smell than we do, and there’s a pretty good chance that if you have a rodent problem, your furry friend has noticed it before you. If your pet seems to be barking or meowing at nothing, or is acting particularly interested in a certain corner or crevice, it’s possible that they are smelling rodent urine that is too subtle for you to detect. The smell of a dead rodent carcass is unmistakable, and a sure sign that you have a rodent problem. If you smell a strong, pungent odor that is different from the scent of urine, it’s likely that a rodent was trapped between the walls or in some other hidden area and died there. If this is the case, call a licensed pest control company to remove the body, as handling it yourself can be dangerous and expose you to several diseases.

Keep an eye out for teeth marks around your house as well. Unlike humans, rodent teeth never stop growing, forcing them to constantly chew on things to keep their teeth whittled down and their jaws strong. Although they are not picky, rodents are especially fond of chewing on wood, cardboard, plastic, and food containers. You can differentiate mouse bite marks from rats by the size—rats have larger teeth and will leave larger bite marks, while mice leave smaller marks. It’s also possible to tell how long the infestation has lasted by examining the marks—unlike their droppings, rodent gnaw marks start out light and grow darker as time passes.

Rodents like to have warm nests made of soft materials where they can give birth to babies. In order to build their nests, they will scavenge scraps of whatever material they can find, such as paper, clothing, cardboard, and much more. Nests tend to be located in warm, hidden areas, so make sure to do regular checks of your attic, basement, behind appliances, and underneath floorboards. Faint scratching and scuffling noises coming from your walls or roof in the middle of the night are also a sign of rodents. Since they are nocturnal, rodents tend to be particularly active in the middle of the night, which explains the racket that keeps you up in the middle of the night—they’re probably scurrying from their nests in search of food and water. You may also find evidence that they have been eating bits of fruits or vegetables from your garden, or spot burrows among plants or under your garden shed. If you find dead rodents around your house or yard, if your pet dog or cat frequently brings you dead mice, or if you have ever had to face the unpleasant task of fishing a drowned rat out of a pool or hot tub, there’s a pretty good chance that you have a rodent problem on your hands.

Although rodents are mostly active at night, they leave behind telltale footprints that are another good indication of their presence. In general, mice and rats are not particularly clean—if you look carefully, you can spot greasy little footprints, smudge marks, urine stains, or tail tracks. If you want to be extra sure, sprinkle a little baby powder or flour in the area you suspect is being frequented by rodents. If you find footprints the following morning, it’s a pretty good indication that you might want to call your local pest control experts.

Why are rodents cause for concern?

Sure, rodents can be annoying, but are they really that much of an issue? Although they might not seem particularly menacing, rodents can not only cause thousands of dollars in damage to your home and property, they can also spread life-threatening illnesses and introduce dangerous parasites to your household.

When the weather gets cold, rodents set their sights on finding a warm home for the winter. They will not hesitate to worm their way into houses and residences by chewing through the exterior, resulting in gaps that can lead to water leaks, allow heat to escape, and provide other pests with easy access to your home. If rainwater leaks into your house through these gaps, you may find yourself dealing with some serious water damage—water spreads fast, and will soak into floors, walls, furniture, wood, drywall, and many more materials around the house. Water damage is difficult and costly to undo, so it’s important to conduct regular checks of the exterior of your home to make sure there are no gaps or cracks caused by rodents.

Once they are inside, rodents will build warm, soft nests using materials they scavenge from around your house. You may find that your favorite book or a file containing important documents has been shredded by rodent teeth. Rodents have also been known to steal bits of drywall, insulation, and wiring to build their nests, which can ultimately be extremely dangerous—exposed electrical wiring can lead to a house fire. Some types of rats like to burrow underneath houses, compromising the foundation and structural integrity of your home, which can lead to expensive long-term damage. Other rats prefer attics and roofs, chewing holes that can lead to water damage and insulation issues.

Aside from the structural and property damage rats can cause, there’s also the question of you and your family’s health. Rodents are a major health hazard, as they can carry several serious illnesses that can be spread to humans through contact with their urine, feces, or saliva. One a rodent is inside your house, they will search for food, and can use their sharp teeth to gnaw through most types of packaging. If they get into your food, it’s almost certain that they have left behind unpleasant traces of feces and urine in and around your food. Human consumption of contaminated foods can lead to several serious, potentially life-threatening illnesses, the most common of which is salmonellosis, which occurs when a person consumes food or water that is contaminated with rodent feces, and can lead to diarrhea, fever, and abdominal cramps. Other serious illnesses caused by rodents include leptospirosis (transmitted by rodent urine, and results in severe flu-like symptoms), Weil’s disease (a serious form of leptospirosis that can result in organ failure, internal bleeding, and death), and rat-bite fever (caused by a bite or scratch from an infected rodent).

Along with these illnesses, rodents can also introduce parasites to your home. Fleas, ticks, and mites are fond of feeding off mice and rats, and may hitch a ride into your house with the rodents. These parasites can then latch onto you and your pets, leading to unpleasant itches and an array of illnesses. Ticks are the most dangerous of these parasites, as they can spread deadly illnesses such as Lyme disease, Rocky Mountain spotted fever, and tularemia, many of which can cause lifelong health complications.

How do I prevent a rodent problem?

As the old saying goes, prevention is better than cure, and this is certainly the case when it comes to rodent control. Once rodents have moved into your house, it can be expensive, time-consuming, and difficult to get rid of them, so make sure you are taking the proper precautions to ensure that your house is rodent-proof. A good rodent control strategy involves three main tenets: rodent-proof construction, sanitation, and population control.

Keep in mind that rodents don’t need much to gain entry into a house—mice can enter through holes the size of a dime, and rats can squeeze through holes the size of a quarter. Inspect your home regularly to make sure that there are no convenient entry points. Once a rodent has gained entry to your home, they breed rapidly, so a small population can quickly turn into a major infestation. Rodent-proofing your home is a major and highly effective means of rodent control, and may save you thousands of dollars in the long run. There are several key spots to check for gaps: on the exterior of your home, check the roof, around windows and doors, around the foundation, and in attic and crawl space vents. Inside your home, check underneath and behind cabinets, refrigerators, and stoves, around water heaters and furnaces, and in attics, basements, and crawl spaces. Seal any cracks in walls or under doors and windows, and make sure to also seal any openings for water pipes, electric wires, sewer pipes, drain spouts, and vents. Double check windows, screens, and doors to ensure there are no gaps. When sealing gaps, avoid materials such as wood and plastic, as rodents can easily chew through them. Instead, opt for steel wool, sheet metal, or wire screens, which are much more difficult for rodents to gnaw through.

Sanitation is another major aspect of preventative rodent control. Rodents are primarily attracted to food and shelter, which means that you should cut them off from any food or shelter they may find in and around your home. Loose food and cluttered, dirty areas make for an ideal rodent habitat, so clean up regularly. Be sure to carefully store all food (including pet food) in sealed, airtight containers, and make sure there are no crumbs or spills that can attract rodents. Rodents love sources of water, so do regular checks of gutters, leaky hoses, outdoor faucets, and birdbaths, and empty any sources of standing water if they are not in use. Store pipes, firewood, and gardening tools neatly off the ground to deter rodents from nesting there. Keep trees and bushes trimmed so that they are not easy hiding spots from predators, and so that rats cannot easily jump onto your roof from a nearby tree. Even if you seal away all the food in your house, there are still outdoor sources of food that can attract pests. Gardens and fruit trees are easy sources of food for rodents. To prevent your fruit trees from becoming a rat hideaway, clean up fallen, rotting fruit regularly, and keep rats from climbing the tree by installing a rat guard (a two foot tall piece of sheet metal that wraps around the trunk). Another easy trick is to plant plenty of mint in and around your garden—rats and mice detest the scent of mint, and will avoid any areas that smell of it. Alternatively, you can spray fox urine around the garden (you can find it in most hardware or garden stores) to deter rodents. If that doesn’t work, build a wall around the perimeter of your yard—it doesn’t have to be very big or fancy, just a wide barrier made of cement or rock to keep the critters out. If all else fails, head to your local animal shelter and bring home a feline friend. Rodents are terrified of cats, and their scent is enough to keep them away from your house and yard.

What are the basics of rodent control?

You’ve tried all the tips and tricks to keep your home rodent-free, but the tricky little creatures somehow still managed to find their way into your house—what do you do now? There are several ways for you to control rodents that have made their way into your home, with traps being one of the most popular and effective ways. Wooden snap traps are the most common, the least expensive, and can be reused, although some people prefer single-use plastic snap traps, which are easier to set and clean. However, the type of trap is less important than the location of the trap. When placing a trap, go for areas that are warm, secluded, and show signs of rodent inhabitation, such as gnaw marks and droppings. Place the traps in frequently traveled areas that are between their nest and food source, making it more likely that they will trigger the trap. Nuts, dried fruit, peanut butter, and cheese are great options for bait. Fasten the bait to the trap with string, wire, or even glue, and make sure that the trigger is sensitive enough to spring when the bait is taken.

If you have a Norway rat problem, place the traps close to walls, behind appliances, and in dark, secluded corners. To trap roof rats, go with higher locations such as ledges, shelves, beams, and rafters, which are areas that roof rats frequent when coming down from their nests to find food. It’s better to use too many traps than too few, and risk allowing a few careful rodents to escape and repopulate. If you have a serious infestation, ten to fifteen traps may be necessary to make rodent control an easy and effective process. Electrocution traps, while more expensive than snap traps, have also proven to be quite effective. These traps work by sending an electrical current through the rodent, stopping their heart quickly and humanely. If you don’t want to use traps that will kill the rodent, live traps are an option; however, they are not recommended. If you use live traps, you will need to either kill the rodent yourself, or release it into the wild, which may cause harm to local wildlife. If you are dealing with mice, a glue trap might be a good idea—glue traps are not great for larger rats, as they may be able to struggle and free themselves. Additionally, if you are using glue traps indoors, pets and children may get into the trap and track the glue around the house. Generally, lethal traps are a much better and more efficient option.

Although trapping is recommended as the best way to control a rodent population, you may have to resort to rodenticides if you have a major rodent problem that doesn’t seem to be affected by trapping. Rodenticides are essentially poisoned bait that is available pre-packaged to minimize the risk to wildlife, pets, and children. If you are using rodenticides, it’s important to remember that there are several safety hazards: many of the poisons used in rodent control are toxic to pets as well, so keep the bait in areas that are inaccessible to pets and other wildlife. Some poisons can remain active in the rodent’s body even after they are dead, making it possible for pets or wildlife to be poisoned from eating rat carcasses. To minimize risk, keep your pets away from dead rodents, and bury the dead rodents immediately. When handling a dead rodent, always wear gloves and a mask, and dispose of them by burying them or sealing them inside a plastic bag and then placing them in the garbage.

Rodents, like most animals, have a variety of natural predators that may help control their population. Snakes, hawks, and owls all feed on rodents, and encouraging their presence may help you control your rodent population. Barn owls in particular are effective and efficient hunters, with a single family killing up to 3000 mice a year. In order to encourage barn owls to live on and around your property, install a nesting box in an area with lots of rodent traffic. Ultimately, a combination of prevention, traps, and natural predation will go a long way towards eliminating your rodent problem.

How do I know when to call the experts?

If you do spot the telltale signs of rodents in your house, it may be tempting to simply set a few traps and wait it out. However, the problem may run much deeper than you think—rodents are tricky, suspicious creatures, and it’s difficult to completely eradicate an infestation without professional help. Although rats have poor eyesight, they make up for this with their other senses, which are extremely sharp. They are also surprisingly intelligent, and tend to memorize locations of food, water, shelter, and obstacles. This makes placing traps difficult, as they are cunning enough to avoid new objects and foods. Even if you do succeed in catching several rodents, it only takes a few suspicious ones to elude the traps and repopulate your house. What’s more, trying to handle a rodent infestation on your own can be both dangerous and ineffective—ultimately, it’s much better to call pest control professionals, who will be able to take care of your infestation, regardless of size or location.

If you call a pest control company, they will start by assessing the issue to determine the size and severity of the problem. Since they are experts, they will have a much better idea of how to go about handling an infestation than the average homeowner will. Then, once they have examined the infestation, they will use an effective combination of methods, including trapping, baiting, and rodenticide to eliminate the pests. Finally, after the extermination, a specialist can examine your home for any potential entry points that may lead to a future infestation, and can help you plug gaps and cracks that can be accessed by rodents.

Hopefully, this guide was a helpful tool that can help you control your rodent problem using a combination of preventative measures, deterrents, and elimination. However, you don’t have to struggle alone!
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