They have caused such problems throughout history that their very name is an outburst, a four-letter word: Rats! They’re an original pest, invading our homes, contaminating our food, damaging property, and even spreading disease. To avoid these problems, here is how to get rid of rats outside, a guide to attack them before they knock on your door.
Signs of a Rat Infestation
Not sure whether you have rats roaming about? Look out for the following signs of rat activity:
- Rat droppings
- Gnawing through wood on buildings or other structures
- Noises from the attic just after dusk
- Rat nests
- Rodent burrows among garden plants
- Damaged vegetables in the garden
- Rats traveling along utility lines or fence tops at dusk
- Rat burrows beneath compost pile or garbage can
- Evidence of digging under outdoor buildings or doghouse
If you see some of these signs of rat activity outside the house, it’s time to take action to control the rat population on your property.
3 Ways to Get Rid of Rats
As a species, rats don’t have much that works in their favor: “There’s not much good about them,” says Bob Pierce, Fisheries and Wildlife Extension Specialist with the University of Missouri. Just seeing one scurrying across your kitchen floor is enough to make you jump, to send a shiver down your spine.
And the trick to controlling them, he says, is keeping a clean property and catching their tell-tale signs early. Rats, mice and other rodents rank right up there with bed bugs and termites as among the most damaging infestations a homeowner can deal with.
Since you don’t want to wait for rats to move into your house to take action, here are some guidelines from the University of California’s Integrated Pest Management (UC IPM) program to prevent and control rats outside:
- Reduce potential rat habitats by storing pipes, lumber, woodpiles, gardening equipment and other household goods off the ground and making sure they are neatly organized.
- Collect garbage, trash and garden debris frequently, ensuring all garbage cans have tight lids.
- Don’t overfill food bowls of outdoor pets. Feed your pet only the amount of food it will eat at one sitting. Store pet food in a rodent-proof container.
- Trim heavy vegetation, which can be a home for rats and other rodents. Cut back overhanging tree branches to a distance 3 feet from the roof to keep rats from making the jump into your home.
- Clean up water sources. Rats need an ounce or more of water a day. You can keep rats away by reducing or eliminating potential water sources.
- Mow the lawn: This reduces the amount of cover a rat has as it travels along your yard.
- Repair or replace screens around the foundation and under eaves that are damaged or not properly fitting. Provide a tight-fitting cover for your crawl space.
- Seal openings around entry points such as pipes, cables and electrical wires that enter the house through walls or the foundation. Use caulk and gnaw-proof materials, such as steel wool or sheet metal.
- Be sure all windows that can be opened are screened and that those screens are in good condition.
- Cover chimneys with a spark arrester and make sure internal screens on the roof and attic are in good repair.
- Install screening over rooftop plumbing vent pipes that have more than a 2-inch diameter.
- Make sure exterior doors are tight-fitting and weatherproofed at the bottom.
If you’ve sanitized and rodent-proofed your home, but you still have a rat problem, it’s time to move on to population control.
- Limit the rats’ access to food, water, and shelter. It is the most effective method for rat control, according to the UC IPM.
- Traps can be an effective way to control rats. The classic wooden snap traps are simple and inexpensive. Be sure to get traps big and strong enough for rats, Pierce says. Be aware that other animals, including birds, might be caught. You might set rat traps only during the night, when rats are active but many other animals are not.
- Known as rodenticides, toxic poison baits are recommended for extensive rat populations. Rat poisons must be fed daily for six to 10 days. Read the label and follow all steps. Put the bait in low traffic, secure areas, such as under or behind boards, boxes, pipes or cans, and out of the rain and snow.
Remove the baits when all signs of rats are gone. After a month, if there are still signs of rats, skip a month and start again. Stopping for a month helps keep the rats from building up resistance to the poison.
As with any chemical pest control option, don’t hesitate to call in a professional exterminator for expert advice and service.
Caution: Wildlife experts note that rodenticides can be fatal for rodent predators, including hawks and owls, as well as other animals like squirrels and raccoons. They urge homeowners to opt for safer control methods to avoid killing these beneficial animals, noting that by killing these beneficial animals, we will “be fighting a war without allies.”
How to Use a Rat Trap
If you want to have a go at DIY rat-trapping, here’s how to set a rat trap:
- Bait rat traps with peanut butter, a small piece of hot dog, bacon or nutmeat, securely tied to the trigger.
- Set traps so the trigger is sensitive and will easily spring.
- Leave the traps baited but unset until rats get used to them. Letting them get the bait once or twice will help avoid trap-shy rats and mice.
- Set traps close to walls, behind objects, in dark corners and in places where you’ve seen activity.
- Place the trap so that the rat or mouse will travel directly over it in their normal course of travel, usually close to a wall.
- Place traps between 10-20 feet apart in areas of activity.
- Use enough traps to make the campaign short and decisive — 12 or more may be needed for a heavily infested home or building.
Hiring a Rat Pest Control Pro
For rat infestations, many people choose to shy away from the DIY approach and call a professional pest control company. It’s an important, tricky job and those pro exterminators know how to get it right, especially if rodenticides are needed. Professional pest control services can also use non-lethal traps that cage the animal for removal without killing it.
A professional exterminator will charge from $170 to $500 to set rat traps and take the rodents away.
The Scope of the Rat Problem
Rats are among the most troublesome and damaging rodents in the country, notes the UC IPM. Here are a few ways these rodents might have you saying, “rats!”
- Rats eat and contaminate food and animal feed.
- Rats damage structures and property, from outbuildings to homes.
- Rats transmit parasites and disease.
- Rats live and thrive in a wide range of climates and conditions, including the areas in and around homes, buildings, farms, gardens, yards, and open fields.
- Rat burrowing can undermine a building’s foundation and slabs.
- Rats’ gnawing can damage soft metals such as copper and lead as well as plastic and wood.
- Plants in your garden aren’t safe. Rats like to build their burrows in gardens for access to food, water, and safety.
- Rats will gnaw electrical wires, posing a fire hazard.
- Rats go after wooden structures such as doors, ledges, corners, and wall material.
- Rats tear up insulation in walls and ceilings for nesting.
Common Rat Species
There are two species of rat that give American homeowners headaches: Norway rats and their smaller cousins, roof rats.
- Norway rats live under the ground in burrows. Also called brown rats, sewer rats, barn rats or wharf rats, Norway rats can grow to be a foot long and weigh more than a pound. They nest in burrows dug beneath buildings, walks, around ponds and in garbage dumps.
“Norway rats are commonly found where there’s poor sanitation,” Pierce says, including a neighbor’s unkempt backyard. “They’re opportunistic and populations can build up.” Where there’s one rat, there’s 10 or 20, he says. They can have several broods each year, building populations quickly.
- Roof rats live above ground. Also known as black rats (a comment on their coloring), they are smaller than Norway rats. Roof rats are found in shrubs, trees, and ivy outdoors, and in attics, ceilings and walls indoors, and are often seen scampering along power lines or tree branches. Their teeth never stop growing, so they are always gnawing.
Rats pose a direct health risk to people they come in contact with. Among the diseases rats can transmit to both humans and animals include:
- Rat bite fever
- Salmonellosis (food poisoning)
- Murine typhus
Historically, perhaps the disease rats are most known for transmitting is plague. (Don’t worry: In recent decades, an average of only seven cases of plague per year are reported in the U.S.) In addition, “they can carry fleas, other sources of bacteria, and the types of diseases that are caused by bacteria,” says Pierce.
Here are a few fast facts about these four-legged foes:
What Rats Eat
- Rats eat almost any type of food, including pet food, meat and fish. Fruits, nuts, berries, snails and slugs are their preferred fare.
- Rats will burrow in backyard compost piles, which provide a ready food source in table scraps.
- Their favorite habitat is attics, trees, and overgrown shrubbery or vines, especially in mature landscapes around manufacturing buildings or along riverbanks.
- Rats are primarily active at night. If you see one during the day it’s likely the sign of a burgeoning population.
- Rats are quick, agile and hard to catch. They also routinely travel as much as 300 feet to feed, making it a challenge to find their nest.
- Roof rats can live around one building but feed at another. At night you can see them running along utility lines or fence tops.
- Rats are accustomed to being near humans. “As long as they feel welcome around your place, they’ll stay around,” Pierce says.
The common house mouse thrives in fields and crops as well as your home, according to the University of Missouri Extension. They will eat and contaminate food, damage buildings, and are known to transmit diseases such as salmonellosis.
Squirrels and chipmunks, which can cause similar problems as their rodent cousins, are capable of moving into a house, creating problems.
The treatment for the house mouse, squirrels, and other rodents is the same as for the rat.
They may kill individual rats, but they won’t reduce a population. Instinct might say a cat should take care of that rat problem, but while they kill individual rats, they don’t effectively control rat populations as a whole. In fact, rats and mice will often eat food left out for family pets.
No, there’s no clear data to suggest this at this time. Modern, high-tech ultrasonic devices emit sounds too high-pitched for humans to hear, but are said to send rats scurrying for cover. However, rats become accustomed to the sound and the verdict is still out on whether they actually repel the rodents.
Many folks don’t want to have to resort to killing the animals as part of their rodent control plan. But experts don’t recommend the non-lethal route when it comes to rats. They point out that if you catch and release the rat, the problem doesn’t go away, you have simply given it to someone else to handle.
Glue traps aren’t recommended. The rat does not die quickly; often, you will have to kill it, probably hitting it with a club or stick. Also, pets and other animals, such as birds, can get stuck to the glue. The Centers for Disease Control and Prevention also warns that stuck rats will urinate, spreading more germs.
Against Rats, Don’t Delay
If you see rats or the signs of them, don’t delay. You want to attack them, and then you want to take steps to keep them from coming back. Stop them outdoors, so you don’t have to fight them indoors. Be willing to bring in a professional pest control company.
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