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Happy Valley is a beautiful place to call home. The picturesque backdrop of Mount Scott, our city’s trademark extinct volcano, and the vast trails and scenic views available in Scouters Mountain Nature Park contribute to the allure of Happy Valley.

Since its incorporation in 1965 with just over 300 residents residing mostly in rural areas, our community has grown to become a thriving suburb and home to over 20,000 residents. Happy Valley continues to grow, and is now one of the fastest growing cities in the Portland Metro Area.

As the population in Happy Valley has increased, our pest control team at Aspen Pest Control has received an increasing number of requests for mice control. There are many factors that lead to mice infestations, and home density is often one of them. Sometimes, when a large construction project is underway, it can disturb outdoor areas that were home to mice and persuade the rodents to take up residence inside homes or businesses.

Luckly, ridding a home of mice is not an impossible task. Understanding how to prevent mice from entering a home and what to do if you notice the signs of mouse activity are the first steps to ensuring your home and business remain free of the pests.

Why do mice come indoors in when the weather cools?

Contrary to popular belief, most mice prefer to live outdoors. But, as the weather cools and their food sources begin to become more scarce, mice look for a warm location with reliable sustenance. To most humans horror, this safe haven often ends up being inside of our homes.

How do mice get inside homes?

Mice are incredibly capable and adept when it comes to breaking and entering. The rodents can swim, they can jump a full foot into the air, and they are able to run and climb just about anywhere.

Mice enter through cracks in a foundation

Mice are able to squeeze through a hole that is just ¼” or larger (about the size of a dime). Foundations that are in need of repair, especially stacked stone foundations are a common entry point.

Mice enter through attached garages

Garages tend to be less secure to the outdoor environment than the livable space within your home. Garages also tend to collect clutter, which provides a desirable hiding place for mice. Once mice have gained access to a garage it is very easy for them to find their way inside of a home. Mice will also frequently find access to food inside garages such as dog/cat food and general food storage.  It’s very important that if homeowners are going to store food in their garage, that they use sturdy airtight containers.

Mice enter through downspouts and gutters

Mice are incredible climbers, so they can easily get to the roof of your home by climbing up downspouts or electrical wires to the roof of your home. Once on the roof, mice look for entry points in in siding and soffits and often gain entry to attic spaces.

Mice enter through chimneys

Any uncapped or improperly capped chimney provides a way for mice to enter your home. Mice and other rodents cannot typically pass by a functioning damper, but once the damper is opened the rodents have easy access to the interior of a home.

Mice enter through gaps around windows

Many homes have gaps around window frames. Check your windows for any gaps larger than ¼ and seal these entry points.

What are signs of a mouse problem?

Many times a mouse problem is identified not because the rodents are seen, but because signs of mice are evident:

  • Mouse droppings are evident in high traffic areas
  • Gnaw marks on hard surfaces like drywall, wooden furniture and cupboards
  • Evidence of mouse active in dry foods including teeth marks and torn packaging
  • Sounds of mice coming from inside the walls, usually at night
  • Oily marks on walls left behind from the natural oils present on mouse fur
  • Pets staring or whining at a wall for an unknown reason
  • Strong scent of urine in high traffic mouse areas
  • Presence of mice nesting materials
  • Broken pipes and damaged HVAC

Are mice dangerous?

Mice carry a number of dangerous diseases which can be transmitted to both humans and pets. The diseases are transmitted through contact with mouse urine or feces, contact with live or dead mice, breathing dust that contains mouse urine or feces, and contact with nesting materials.


Leptospirosis is a bacterial disease that can lead to kidney damage, liver failure, respiratory issues, and even death. The disease is passed to humans and animals through consuming food that is contaminated by mouse urine or feces. The disease can also be transmitted when contaminated water comes into contact with mucus membranes.

Salmonella Infection

Salmonella is a bacterial infection that lives in the digestive tracts of mice. It is commonly passed on to humans when they eat food off of a surface that is contaminated by mouse urine or feces.

Hantavirus Pulmonary Syndrome

Hantavirus Pulmonary Syndrome is respiratory disease in humans. It is severe and can be fatal. The disease is passed to humans through a number of ways, most commonly through breathing in kicked up dust that contains mouse urine and feces. HPS is also transmitted through direct contact with mice, contact with their urine or feces, and less often through bite wounds.

How do I get rid of mice in my home?

Once you have mouse activity inside of your home, there are two primary methods for ridding your home of mice, trapping and poisoning. Perhaps the most important consideration is not allowing mice to enter in the first place. It’s not possible to seal up every entry point, but taking precautions to seal cracks and fill holes can make a big difference.

Use of mouse traps

Traps work well, but homeowners often underestimate the number of traps required to do the job. If traps are the only method being utilized for rodent control, never set less than 12 traps and always buy more than you anticipate using. It’s important to have a plan for rodent removal in place before the mice are trapped. If a clear plan is in place, anxiety will be lessened when a dead carcass is found.

Traps should be set in locations where you have noted the presence of mice. Place the traps along walls, as mice prefer to travel along walls. The bait end of the trap should face the wall and the traps should be set every 1-2 feet along the wall in high traffic areas.

Make sure that you’re using bait that is desirable to mice and not too much of it. Most people assume that mice prefer cheese, but that’s just in the cartoons. Good options for bait are seeds, nuts, a small amount of peanut butter, hazelnut spread or chocolate.

It’s a common myth that mice prefer cheese. Bait traps with nuts, seeds, peanut butter or candy. A cotton ball soaked with a little bit of vanilla flavoring is also a good bait option.

How to use mouse poison

The use of poison and bait stations can also work well to control a mouse infestation, but it’s imperative to use those products safely. Read the label on the packaging and follow the instructions exactly.

If pets and/or children are present in the home, extra precautions are necessary. The poison should be placed in an area that is inaccessible and it should be secured to a surface it cannot be picked up and removed.

For many, the process of trapping and baiting is an unpleasant and intimidating task. For instance, many homeowners would rather not enter their crawl spaces to set  bait. This is an important step as the crawl center is often a location of intense activity. A consultation with a pest control company can be the best way to understand the size of the problem, construct a plan to treat it, and ensure a successful outcome.

Who can I call to address a mouse problem in Happy Valley?

Aspen Pest Control LOVES serving our Happy Valley community including family homes and businesses. We have successfully treated many homes in Happy Valley for mice. We offer free, no pressure estimates and same day service for no extra charge. Our results are 100% guaranteed and we use products that are safe for your family and pets. Contact us to discover why your neighbors in Happy Valley are loyal customers of Aspen Pest Control.

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