Homeowners Guide to Mice

The house mouse is a small mammal in the rodent family. They are found throughout the United States, usually living in proximity to humans, in or around houses or fields. House mice range in size from approximately 2 ½ to 4 inches in length and are dusty grey in color with a long pointed snout, small rounded ears, and a long hairless tail. In New Jersey, as almost everywhere, the house mouse is the most common rodent pest. Even just a few mice have the potential to become a significant problem once they enter a home. Considering that a single female mouse can have thirty-five offspring in just one year, a seemingly small mouse problem can quickly escalate into a large-scale infestation.

How Do You Know You Have Mice in Your Home?

Often, one will find signs of the presence of mice in your home before actually observing the stealthy rodents themselves. One common sign is the “gift” mice leave behind, mouse droppings. Mouse droppings are distinctive rod-shaped s pellets that range from 0.1 to 0.25 inches in length. Recent mouse droppings are dark in color (looking almost black) and soft in texture. Over time, mouse droppings become harder and lighter in color and may even crumble when touched. Since mouse droppings are found wherever mice have been, the best places to inspect are along baseboards, near any clutter in your home, and in areas where food is stored. 

Since mice are on a constant quest for food, signs of mice are often found near food, as a customer in Middletown, NJ found. Although in the wild, a mouse’s natural diet consists of seeds and insects, they are very adept at finding other food sources inside homes. A common sign of an infestation is damaged food goods. Mice will gnaw on the sides of packages, such as cereal boxes, to gain access to the food. Food is often pulled from the packaging and will be found scattered on the floor.

In addition to visual signs, there are auditory ones as well. Mice are very skillful climbers and are able to fit into small spaces. They can easily climb through the wall voids and floorboards of a home. Wall voids are common routes to nests found in attics or other quiet and relatively undisturbed places. During the evening hours, especially when it is dark and quiet, you may hear gnawing and scratching coming from inside the walls, or a faint sound of running across the ceiling.

How Do Mice Enter Your Home?

Mice are burrowing animals. Their body shape and size are designed to squeeze into very small holes. In fact, a house mouse is able to climb through a hole that is just slightly large than a pencil in width. There are many misconceptions about how a mouse is able to “shrink” and fit into such a small hole such as mice having  “collapsible skeletons.” This is not the case. Mice are very small and their fur makes them seem larger than they actually are. The largest part of a mouse’s body is its head. Since the mouse has no collarbone, if a mouse is able to get its head through an opening, the rest of the body will fit.

Why Do Mice Enter Homes?

Mice enter homes to find shelter, food, and water. Here in New Jersey, the fall is a very common time to encounter a mouse in the house. As the weather turns colder, house mice seek out shelter for the winter months. House mice prefer to create their nests in dark secluded areas like attics and the wall voids of your home. House mice use paper products, cotton, packing materials, wall insulation, and fabrics to create their nests. All of these materials are readily available in most homes.

House mice are highly adaptable creatures and will happily eat human and pet foods found in homes instead of their usual diet of seeds and insects. Using their strong jaws, mice can easily gnaw through cardboard containers, such as cereal boxes, or paper sacks such as those used for flour and sugar. 

Mice also enter homes in search of water. Most of the water mice acquire is through the water contained in scavenged food particles and crumbs. Mice are able to jump more than a foot in the air and are excellent climbers so these morsels of food can be found on the floor, on countertops, in cabinets, pet food bowls, unsealed food containers, and more. In short, if there is open food or food in paper or cardboard containers, there is a good chance that a mouse will be able to reach it.

How Do You Prevent a Mouse Infestation?

Mice enter homes through very small holes so it is important to seal as many holes as possible.  Be sure cracks are sealed with silicone or silicone-latex caulk. Any hole that is the width of a pencil or larger should be filled. If the holes are around utilities fill them with steel wool to prevent mice from accessing the home. Installing door sweeps on your exterior doors will also help prevent mice from entering. 

The screens in windows and sliding glass doors must also be checked. A small hole in a screen can not only let in bugs but it a potential entranceway for mice as well.  Proper drainage at the foundation of your house as well as gutters that channel water away from the structure will prevent potential nesting sites.

It is important to make your home inhospitable to mice. Keep food sealed in containers with tight sealing lids. Mice seek out clutter as places to hide so keeping papers and boxes off the floor is an important part of prevention. 

Why is an Infestation Dangerous? 

Don’t be fooled by their small size. Mice can cause serious damage to a house and to its occupants. These mammals are named rodents, which means “gnawing animal” (Latin rodere, to gnaw) because of their large incisor teeth that grow continuously and must be worn down by gnawing. Mice are indiscriminate as to what they gnaw. They gnaw on woodwork but they also have been known to gnaw on electrical wiring.  Mice-damaged wiring can spark electrical fires, destroying homes

Mice can also bring serious diseases into homes including salmonella, hantavirus, and leptospirosis.  Even small droplets of mouse urine can cause allergies in children. As well as being nuisances in their own right, mice can transport disease-carrying fleas, mites, ticks, and lice into your home.  These parasitic pests bite and bring with them a number of different diseases, most notably Lyme disease from deer ticks. For the health and safety of the occupants of a home, it is important to keep your home mouse-free.