Why Are There Suddenly Insects in My Home in Winter?

By Chris Williams on February 14, 2017.

It’s February and you’re suddenly seeing strange bugs in your house. Since there’s snow on the ground outside, does that mean that you have an infestation in your house? The bugs obviously didn’t come in from outside (see Why Are There Plant Bugs in My House?).

The bugs probably did come in from outside, but several months ago. You are probably seeing what we call “fall invaders.” These are insects that don’t die off in the fall but instead look for sheltered places to spend the winter. Most of these insects feed on various crops and trees and you might not even notice them outside. When the weather cools in the fall, however, they tend to fly to structures and can congregate there in large numbers on the sunny side of the house.

Your Home Provides a Temporary Winter Retreat

What are the insects we’re talking about? In our Northeast region, fall invaders can be western conifer seed bugs, brown marmorated stink bugs, Asian lady beetles, cluster flies, boxelder bugs, or elm leaf beetles, to name the most common. You should have a pest control professional identify your winter bugs, however, to make sure you don’t have a different type of pest entirely.

These invaders find their way inside through cracks and crevices, vents, unscreened windows, gaps under doors, etc. They most often enter around the roofline and many never get further than the attic. Or, they may end up in wall or ceiling voids, behind draperies or baseboards, or any other hidden place, where they become relatively immobile.

You may have dozens of fall-invading insects overwintering in your house and never know it. Come spring, they gradually “wake up” and look for a way back outside (see It’s Time for Insects Wintering in Your Home to Wake up!). We get calls when this spring migration occurs, of course, but we can also get calls in January and February. If we get a stretch of unusually warm and sunny days, some of the bugs are fooled into an early awakening. They emerge from hiding and bumble around lethargically. They head for windows and lights.

Plan Ahead to Avoid Overwintering Insects Next Year

So, what can you do? That depends on the numbers of bugs you’re seeing. For a few, just vacuum them or swat them (I would say put them back outside, but at this time of year they won’t survive anyway). If you discover that you have a large number of bugs overwintering, say in your attic or a wall void, we can treat those spaces to kill the invaders.

The best time to control fall-invading insects is in late summer. At that time, you should make sure that any openings into your home are sealed. You can also have Colonial Pest treat the outside perimeter of your home to intercept any of these insects that are congregating prior to moving inside (see Take Steps Now to Keep Fall Pests Outside!). Call us to set up a treatment schedule to keep overwintering insects out of your home next fall.

Photo Credit : By Jared BirkOwn work, CC BY-SA 3.0, wikipedia



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