This is the time of year when ladybugs look for a warm, cozy place to spend the winter. You may be seeing ladybugs in your house, clustered on windowsills, crawling along the walls, flying from room to room and generally being a nuisance.
Ladybugs are useful insects in the garden as they eat a variety of insect pests that would otherwise eat your plants. But they have no business being in your house. Native ladybugs usually spend the winter nestled in groups amongst leaf litter or they will sometimes even find a cave for their winter home. It is the non-native Asian lady beetles who make such great efforts to spend their winters inside our homes with us.
Some of these Asian lady beetles will expire over winter, and their carcasses can leave stains behind, not to mention the bad smell they exude. They can make quite a mess and get themselves into all sorts of places they shouldn’t be, like your computer keyboard. If enough of them mass together, they can even clog pipes and vents.
The best way to get Asian lady beetles out of the house is to prevent them from entering in the first place. They can crawl in through the smallest cracks, so seal windows with caulk; add weather-stripping around doors and place fine screens over any openings into the attic and soffits. As you bring your gardening tools and yard decorations inside for the winter, check them to make sure there are no ladybugs coming inside along with them.
If ladybugs do manage to get inside the house, they can be vacuumed up. If you are vacuuming up ladybugs, either remove the dust bag immediately and deposit it in an outdoor trash can or wrap a plastic bag over the end of the vacuum hose so the ladybugs don’t crawl right back out.
Avoid swatting ladybugs as they are likely to stain whatever they were squished against, and their yellow blood can leave an odor that smells like burnt rubber. You can also try capturing the ladybugs and releasing them outdoors, but they are likely to try to come back inside. If ladybugs are clustered on the siding of your home, they are waiting for an opportunity to enter your home. Knock them down with a strong spray from a hose.