How to Plug Rat Holes

Finding rats inside your home is not a welcome occurrence — they can get into your food, make your home unsanitary, and carry diseases. Though rats can be quite large (some even measuring up to 1 foot in length), they can enter your home through an opening as small as a quarter in their quest for food and shelter.

Have a rat issue and not sure where to start? The best way to handle a rat infestation is to plug the holes that serve as entryways into your home.

Rats and mice enter your home through holes and gaps in many different areas of your house. When you find a hole that a mouse or rat can fit through, it's important to seal it with a material they can't breach.

Steel wool is an excellent material to use for small holes both inside and outside your house because it is strong, and rodents dislike chewing it. Steel wool is flexible and nontoxic, so it is safe to use in homes with children and pets. Use medium-grade steel wool, which is durable as well as a good balance of flexible and firm. (Lower-grade steel wool is too soft, and rodents may be able to get through it while higher-grade wool may be difficult to place in small holes since it is less pliable.)

Completely block the hole by pressing as much steel wool into it as possible and applying caulk to keep the plug securely in place. As an alternative to steel wool, you can use copper mesh, such as Stuf-fit brand, or screen wire, which can be balled up into the hole to provide a temporary plug that can be used indoors and out.

Another option is to add a fast-drying patching plaster or anchoring like Fixall and mix it into a bundle of copper mesh or steel wool to strengthen it. Then push it in to plug the hole and smooth over the exterior. A Presto Patch can be used indoors to seal over the mesh and cover the hole. Another solution is Strong Patch, a drywall repair patch for indoor use. This is a kit that contains backing material consisting of a sheet metal patch and compound to cover up and seal holes. Following application, sand it and paint or wallpaper over the area for a seamless finish for indoor holes.

Another great choice for holes up to an inch in diameter is using an insulating foam sealant such as Pest Block. For larger holes, you can use wire mesh screen and Pest Block together to reinforce the hole. When applying Pest Block, do not fill up the hole completely since the insulating foam will expand approximately 150 percent when drying. This can be used on both indoor and outdoor holes. Wear gloves and goggles for safe application.

There may be spaces around electrical cables, electrical conduits, cable lines, telephone lines, dryer exhausts, or gas, water, or steam pipes, which can be filled with caulk or expanding foam. Be sure the filler or sealant is heat resistant if the pipe or duct gets hot so that it functions properly and is not a fire hazard. You may need water-resistant caulk or sealer in some cases. Check the label to select interior or exterior use as needed and wear gloves and goggles when applying.

It can be kind of difficult to plug a rat hole if you're not even sure where exactly they're coming in. Here are a few ideas of where these pests like to invade your home.

One of the first places to check for rat holes is in your basement or crawl space. Check the basement and laundry room floor drains and dryer vents, pipes by any bathroom sinks and the washing machine, and the pipes leading to air conditioners, water heaters and furnaces.

Roof rats are excellent climbers and can easily make their way up to the roof ⁠— and from there into your attic ⁠— via tree limbs. Check along the attic walls and any crawl spaces nearby. Inspect the insulation for nests and burrows or damage caused by rodents. Look for holes in soffit vents or covers. Check any vents in the attic as well. There may be holes in the gables, gable intersections, or vents that rodents are entering through.

Your garage can be an easy access point for rats since they can sneak in when the garage door is open or through a small hole at the bottom. Be sure the garage is properly sealed and plug any rat holes you find. Reinforce the garage door by getting reinforced rodent seals for the bottom and sides of your garage door.

Inspect the foundation of your house for holes or gaps. Rats are excellent at digging and burrowing and can make holes in the dirt near your home. Carefully look for holes around gas lines, electrical lines, and cable and plumbing pipes. These can serve as entry points for rats to crawl along.

Rats love the kitchen because they may be able to access food and water there. Check behind the refrigerator and stove, excellent hiding places that are hard for humans to reach. Finish by checking behind, under, and inside your kitchen cabinets and around the pipes under the kitchen sink. There may also be rat holes inside closets or pantries, so check near the corners on the floor.

Rats and mice can enter your home through holes or gaps near windows and doors. Also be sure to examine the fireplace and chimney carefully. Watch for rodent droppings, which may make a trail showing you where they're coming into your home.