Pests and Older Homes

by David Moore
Manager of Technical Services and Board Certified Entomologist

I was recently asked, “Why do older homes get more pests than newer homes?” I told that individual to start a list. Older homes tend to have more activity from a number of pests from boxelder bugs to mice to termites for a number of different reasons. These homes, particularly homes built before 1950, were built with different standards than the newer construction standards we have today. Just the natural settling, constriction and expansion from weather and general breakdown of construction components all contribute to this being a long term issue. Another big issue is that most older homes are attached to older municipal infrastructures and are typically surrounded by other older homes. All of these items are just a summary of potential items that can impact the pest potential at a home. I am going to review some of the items to look for that can impact an older home’s pest population and how to resolve them. 

So how can someone prevent or fix these issues on their home? The first thing you need to do is seal up as many cracks and holes around your perimeter as you can.  Insects do not need more than a few millimeters and a mouse only needs a ¼ inch hole to penetrate a home. If you take a weekend and seal up as many holes and cracks that can be located, you will put yourself many steps ahead of any would be intruders. Some concrete for a patch or some silicone or caulk will generally do the job. For larger projects, sometime you will need some tin flashing or something else to correctly fill a larger hole. Do not use expandable foam or steel wool since they break down with the elements. Additionally, rodents will chew right through expandable foam. 

Don’t forget about your windows and doors as well. Door sweeps create a barrier to prevent pests from entering the property. If the door does not close properly, it can allow many different pests into a home. One quick way to see if your doors are sealed up well is to look at them from the outside at night. If you see light coming through around the perimeter, then there is a gap that needs to be fixed. As the caulking around window frames degrades, numerous pests can pass through them. 

Water can also play a big role in pest activity. Gutters, drainage, and leaks can all have an impact on a pest population at a home. Water can lead to mold and fungi, which many insects feed on. It can make construction material easier to get through and attract insects to a home as well. Cleaning out your gutters so ants don’t live in them is something not many people think about, but it happens. By cleaning them out, you will also allow the water to flow properly, reducing the potential for damage to the wooden parts of a home. Having proper drainage away from your home will help reduce the attractiveness of your property as well. If you have leaks in a crawl space, taking the time to have them fixed can make a huge impact on a pest population. Another item in the crawl space that can have an impact on the pest population is to have the air moisture content in your crawl space properly maintained with an Atmox system or something similar. Many insects require moisture enriched areas, and if you make it more arid, they will be less interested in your property. 

One of the big dangers for an older home is additions or improper modifications to a property. If someone added a patio or another room without having a termite treatment done to that area, then that ground has been compromised and could be attacked. If plumbing was done incorrectly, then rodents can enter a home through the sewer system. If a roof was not installed properly, then there may be a gap that squirrels or bats can move in as well.

This was just a quick list of common items that older homes run across, and you may not have any of these items. The idea is to use an ounce of prevention to be proactive and not need to spend a pound for the cure. It is a lot less expensive and time consuming to be proactive than it is to wait until you have a problem and have to get it fixed and any subsequent damage to your property.