Signs That a Residence May Be Infested by Rodents

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Mice and rats are drawn to houses to find food, water, and shelter. The reality is that if you are in the market looking to buy a home, you need to be alert to the possibility that a property has an issue with mice or rats.

There are some important warning signals that you need to be aware of when it comes to the prospect of a rodent infestation.

Specific Signs of a Residential Rodent Issue

signs of a rodent infestation
Here are some common signs that the house you are looking at could have a rodent infestation!

Signs of a rodent issue to be on the lookout for include:

  • Gnaw marks
  • Droppings
  • Urine Odor
  • Greasy trails
  • Scratch marks
  • Scratching sounds
  • Squealing sounds
  • Scurrying sounds



A primary reason why certain animals are classified as rodents is because of their incisors. The incisors of rodents continually grow throughout a mouse or rat’s lifetime.

Consequently, these animals need to gnaw of objects in order to keep their incisors in check. In addition, rodents gnaw of the structure of a home itself in order to gain access to a residence in the first instance or to be able to forage about a house in search of food and water.

Finally, rodents will gnaw on other objects, particularly packages that contain food.

When it comes to gnawing on the structure of a residence itself, gnaw marks are more commonly found along the exterior walls of a home, near the foundation. In addition, they are likely to be found along the bottom of the walls, near the floor.

Gnawing may result in holes rodents use for passage. Bear in mind that a mouse can fit through a hole as small as a dime; a rat can get through a hole as small as a quarter.

Rodents are capable of successfully gnawing a wide array of different types of materials. These include:

  • Many types of wood
  • Drywall or sheetrock
  • Brick
  • Plastic
  • Particleboard
  • Droppings

Mouse and rat droppings, or feces, are also signs that rodents are present in a home. Mouse droppings are small, about the size of a grain of rice. Rat droppings are a bit larger. Both types of droppings are brownish in color, growing a bit darker as they age.

When they dry out, rodent droppings can be a grayish color.

You typically will not see rodent droppings in some sort of pile. Rather, they may appear in something of a line located in a place where the regularly walk or forage. For example, you may find rodent droppings along the base of a wall.

Rodent Dropping Carry a Health Risk Too

As an aside, you need to understand that rodent droppings can present a very real health risk. They can carry harmful viruses or bacteria. There are some germs that survive even after rodent droppings dry out.

When they do dry out, rodent droppings crumble very easily. When they crumble, the feces can become airborne and are capable of carrying these germs with the dust. If inhaled, a person can contract some of the germs that are potentially living in rodent droppings.


Urine Odor

A sign of a more advanced rodent infestation in a residence is a urine odor, perhaps rather faint. When a homeowner has put a residence on the market for sale, the prospect of detecting a rodent urine smell is likely unlikely.

Odds are that the homeowner will have taken steps to mask and potentially unpleasant odor in a residence.


Greasy Trails

When rodents are out and about foraging, they tend to leave a greasy looking trail along the pathways they typically traverse.

These trails are created to establish a particular rodent’s territorial zone as well as to identify that rodent’s favored course. You might see greasy looking trails inside a home, usually along the walls of a residence.


Scratch Marks

Another indication that a residence might have a rodent issue is the presence of what can be rather tiny scratch marks.

Scratch marks might be found on a wall. However, they also might be found on the floor.


Scratching, Squealing, Scurrying Sounds

When mice or rats infest a home, they do make sounds as well. These include scratching, squealing, and scurrying sounds. As is the case with a urine odor, you are not likely to detect these noises when at a home showing or open house.

Rodents primarily are nocturnal animals. They are most active from dusk until dawn. Because most home showings and open houses are during the day, the odds of hearing rodents on the premises is slim.


Professional Inspection

If you detect the presence of rodents in a home you’re interested in making an offer on, you do need to inquire of the homeowner.

A homeowner needs to provide you accurate information in response to such an inquiry, whether or not a specific disclosure of a rodent issue (past or present) needs to be made by a seller.

You do need to keep in mind that a homeowner may not actually be aware of a rodent issue if it is of fairly new origin.

You need to obtain an inspection of the premises before you close on a contract for sale. The inspection needs to include an examination of the property for the current or past presence of rodents in the house.



When you are looking to buy a new property, it is vital that you thoroughly check the premises for the signs of a rodent infestation.

Now that you know some of the signs of a rodent infestation, you can go to the viewing armed with information!

Whilst most of the property viewing is likely to be concentrated on the aesthetics, and feel of the property, it is important to cover some of the basics too.

You do not want the first memory of your new home to be the removal of a rodent infestation!

Good luck.


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6 thoughts on “Signs That a Residence May Be Infested by Rodents”

  1. It’s good to know that you might have rats in your home if you notice scratching sounds throughout your home. Whenever my daughter goes to bed, she complains that she hears scratching and scurrying coming from her closet, and she is worried that there is something inside. It may be a good idea to call a pest control specialist who can take a look inside the closet.

  2. I have seen gnaw marks on some food and noticed heard squeaking sounds around my house. I like how you mention rats carry bacterias along with them. Thank you for the information. I’ll contact pest control to verify and get rid of the rats.

  3. I was surprised when you said that a mouse is able to squeeze through a hole that’s only as large as a dime. When I was cleaning the kitchen floor yesterday, I noticed some pretty small holes behind the trash can. Thanks for sharing this info and letting me know that I probably need to hire a mice control professional soon!

  4. Thanks for helping me learn how a house could be infested by rodents. My uncle is about to give my mom one of his oldest properties and I wanted to know if it might be infested by pests. The idea of hearing scratching or squealing sounds in a home is indeed very concerning. I should share this with my mom so she can check if there are any rodent traces, or hire someone to check for us.


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