Keeping Insects Out of Your Home in the Winter

Many other insects, such as the western conifer seed bug, can also enter homes to seek shelter for overwintering. Photo by Mohammed El Damir,

If you’re not a fan of insects and their relatives, colder months can bring a bit of relief from unwanted outdoor encounters. But colder months don’t mean they won’t be present in our spaces. As temperatures cool in the fall and winter, insects, spiders, and other arthropods can seek refuge inside human structures to find warmth and shelter.

Insects and spiders coming into homes in colder months is a common occurrence, but there is good news. The most important consideration is that the insects and arachnids that enter our homes in the fall and winter are often just nuisances. They are rarely organisms that can cause harm to your structure, pets, or people (yes, even the spiders). Taking this into account, it is rarely recommended to treat for any of these insects with insecticides. It is easier to focus on removing the critters you do find and sealing up the house to prevent entry of other critters in the future.

To remove these critters from your home, simply collect them in a cup or container and release outdoors. Be mindful that some insects and spiders can bite. While bites are rarely of medical significance, some individuals can react differently. So, take precautions, especially if you are known to react differently to insect and spider bites or contact.

To seal up your home, think of all possible entry points for small organisms to enter: windows, doors, cracks in the foundation, gaps surrounding pipe entry points, vents, etc. Take time to seal up these entry points with new window screens, new door thresholds and weather stripping, caulk, or other materials as needed. This can also help to reduce your heating bill, so it’s a win-win!

It is always encouraged to learn more about the insect or spider that gets into your home; we are often less afraid of the things we understand. If you would like to learn more about the critter you found in your home, contact the Plant and Insect Diagnostic Clinic with photos or a sample that can be submitted if necessary. If additional action is needed for the specific organism you found, we can offer advice based on your individual situation.

Funnel web spiders can commonly make their way indoors in cooler months. Photo by Joseph Berger,

 Remember that the critters that found their way in are seeking some of the same things we use our homes for in the winter: warmth and shelter. When we place our home in the middle of insect and spider habitat, it can only be expected to come across them at one point or another. So instead of trying to kill them it is usually best to keep them out of our space instead, as preventing entry to our space can be a more permanent solution than treating or constantly killing or removing them individually.


Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on January 10, 2023. The information contained within may not be the most current and accurate depending on when it is accessed.