Rat sticking its head out of a hole. Pioneer Pest Management reveals which pests overwinter in the Portland, OR and Vancouver, WA areas.

Rat sticking its head out of a hole. Pioneer Pest Management reveals which pests overwinter in the Portland, OR and Vancouver, WA areas.

Birds migrate and bears hibernate but what do pests do during the colder winter months? In this blog post, you’ll learn more about overwintering pests, and what you can do to keep them out of your home.

What Does Overwintering Mean?

Before we get into overwintering pests it’s important to know what overwintering even means. Overwinter describes how organisms survive through winter. Overwintering organisms include plants, animals, and insects.

Boxelder Bugs and Stink Bugs

When the temperature begins cooling down in the fall, boxelder bugs and stink bugs will seek shelter so they can ride out winter away from the elements. This includes under rocks and woodpiles and in hollow tree trunks. These pests will also look for dry spaces on your home like cracks or crevices in your home’s foundation and in window moldings. These pests are more of a nuisance. They aren’t harmful to people. You can prevent these insects from invading your home by sealing up cracks in your siding, near roof soffits, and your foundation. You can learn more about boxelder bugs and stink bugs in our helpful Stink Bugs – Boxelder Bugs information page.

Carpenter Ants

These overwintering pests come in brown, red or black and are larger than most ants in our area. Carpenter ant colonies are typically dormant in winter, however, if they’ve found warm shelter, they may skip their overwintering phase and continue on with their daily habits.

Carpenter ants are considered one of the most structurally damaging pests in our area. They hollow out wood to make nests inside. So if you have an infestation, it’s important to address it. If neglected, carpenter ants will significantly damage your home. We talk more in-depth about carpenter ants in our Carpenter Ants informational page.


These cold-blooded insects generally like it outdoors. In fact, when it starts getting cooler, their bodies adapt to prevent them from freezing. They will begin producing protein and glycol compounds in their hemolymph– which is their form of blood. This works similarly like antifreeze for a car. Spiders will shelter under cracks and crevices of a structure, roof or leaf piles and in tree bark. They aren’t drawn to the warmth of a home and typically won’t try to get in your home to “hibernate” for the winter as most people believe. If you do see spiders in your home, they were likely there already, and you are just now noticing.

Spiders like dark, undisturbed places. They may be found under furniture, on ceilings, cluttered areas, and spaces like your garage, attic or basement. You can seal up potential entry points to keep spiders out of your home and keep your home clutter-free. Our Spider Extermination – Removal – Control page goes deeper into spiders. There you’ll find more ways to keep spiders out of your home, learn the different species, and learn what to do if you’re bitten by a spider.


Our homes provide everything a rat or mouse needs to live comfortably through the harsh winter– warm shelter and food. Because they can fit through holes the size of a dime, they can easily get into your home unnoticed. And they’ll find other creative ways to gain access into your home like chew through electrical cables or climb up drain spouts.

Rats and mice are not only a nuisance, but they also carry various diseases and bacteria and they can also cause significant damage to your home because they’ll chew through anything. You can learn more about rats and mice in our Rats & Mice Extermination, Removal & Control page.

If you do end up with a pest problem Pioneer Pest Management can help! We provide professional and affordable pest control solutions for all types of pests. So we’ll help ensure your family and your home are well-protected from pests this winter. Contact us today for a free quote!

Overwintering Pests in the Portland and Vancouver Area in Portland OR and Vancouver WA

Serving Customers on the East Side:

Portland | NE Portland | Gresham | Happy Valley | Clackamas | Milwaukie | Mt Tabor | Belmont | Lloyd Center | Laurelhurst | Hollywood District

On the West Side:

Downtown Portland | Beaverton | Tigard | Hillsboro | Cornell | Sylvan | Cedar Hills

And in the Vancouver WA Area:

Downtown Vancouver | Fruit Valley | Hazel Dell | Felida | Cascade Park | Camas Washington