There's nothing quite like a mouse (or rat) in the house to put occupants on edge. Rodent infestation is a major problem in some areas of the USA, but any house or business anywhere can become home to these pesky critters. Rodents do more than just annoy occupants; they damage property and carry serious diseases. If you suspect an infestation, or even a presence, take action to protect your property and health.

Dealing with Rodent Infestation

The telltale signs of a rodent infestation include:

• clusters of droppings (black sausage-shaped pellets, the size of a grain of rice for mice and somewhat larger for rats)
• gnaw marks on baseboards and food containers
• shredded paper and fabrics (rodent nesting material)
• a musty odor
• squeaking and rustling sounds
• visual confirmation

How do you get rid of these unwelcome guests? When should you use natural methods and when do you need to break out the big guns -- poisons? The good news is that sealing small holes where rodents can get in and trapping them are considered the two most effective indoor control methods. And neither requires any chemicals!

Rodent Prevention 

Clean and Tidy: The best way to stop an infestation problem is to prevent it in the first place. Do this by being a bad host. Don't provide easy access to food, water, or nesting materials. Store food in heavy-duty plastics or glass or metal containers. Keep your garbage covered tightly and don't let dirty dishes sit in the sink. Recycle unused papers, store fabric, and keep items like cotton balls in a glass container. Outdoors, keep your garbage in a receptacle with a tight lid, cut grass regularly, and don't let unused items like boats and cars become rodent “mansions.”

Block Entry: A mouse can squeeze through a hole the size of a dime. Inspect your house, especially near doors, windows, and utility line entrance points. Fill any holes with copper mesh, concrete, brick mortar, or steel wool (a temporary fix). Make sure that all water supply pipes are capped. If you know that you have an infestation and plan to try rodent repellents, wait a few days before patching holes to allow the animals to escape.

Use Repellents: Many natural rodent controls fall under the repellent category. Mice and rats hate the smell of peppermint oil and catnip oil. Natural control method resources, such as "1001 All-Natural Secrets to a Pest-Free Property" by Dr. Myles H. Bader (2002), suggest saturating a cotton ball with one of these oils and placing it near the areas where rodents, or signs of rodents, have been seen. Predator urine repellent is widely available to protect the perimeter of your home from rodents who want to get in, and protect your yard from outdoor pests such as voles and shrews.

However, these and other natural repellent recipes and products receive mixed reviews. Start natural and if you aren't satisfied, move on to chemical repellents. Always follow manufacturer instructions.

Population Control 

Trap: Trapping, combined with blocking entry, is the best way to get rid of the rodent population in your home. There are several types of traps available: snap traps, glue-floor traps, and multi-capture traps. Snap traps provide a quick death. Glue-floor traps cause an extended period of suffering and are criticized for this, but they are effective. Multi-capture traps have a way in, but no way out. Humane traps are also an option; however, you will need to empty them. 

Place traps about 6 feet apart against the walls where you notice activity. It's better to use too many traps than not enough. Bait the traps without setting for several days so the rodents to become used to them. A dab of peanut butter coated with rolled oats is appealing for mice, while ground meat or fish is enticing to rats. Traps should be kept from pets and children. 

Non-Toxic (to Humans) Poison

When you have a rodent problem, a combination of trapping and poisoning to knock down the population is in order. Some people are uncomfortable using poisons of this nature in the house. Online you can find a few recipes that are not toxic to humans, but are lethal to rats and mice. For example, Dr. Bader suggests combining 2 ounces of barium carbonate with 1/2 ounce of granulated sugar and 1/2 ounce of breadcrumbs. Mix in enough water to form bait balls. 

Poison

If all else fails, homeowners can try one of the many poisons available to control rodent populations: Warfarin, Pival, Fumarin, Chlorophacinone, Bromadiolone, or Cholecalciferol. Always read and follow manufacturers' instructions.

If you are using poison as a last resort, you've already done everything to prevent another infestation. If you find yourself back at square one despite your best efforts, it is time to call a professional exterminator. You are probably overlooking something that they’ll be able to detect.

This article was updated November 14, 2017.